• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
Carmy - Easy Healthy-ish Recipes
  • Home
  • All Recipes
    • All Recipes
    • Airfryer
    • Breakfast
    • Freezer Friendly
    • Instant Pot
    • Main Dishes
    • Meal Prep
    • Meatless
    • Sides
    • Under 60 Minute Meals
  • Meal Prep
  • Instant Pot Recipes
  • How To Tutorials
    • Meal Prep
      • Meal Prep 101: Why You Should Meal Prep, How To Meal Prep, and Other Meal Prep Tips
      • Tips To Help You Meal Prep For the Week Successfully
      • Tips for Meal Prepping on a Budget + 28 Recipes
      • Whole Chicken Meal Prep (3 Freezer Friendly Meals)
    • Meal Prep: Learning the Basics E-Book
    • How To Tutorials
      • How To Cook a Whole Chicken in an Instant Pot
      • How To Cook Chicken Breasts Perfectly
      • How to Make the Perfect Hard Boiled Eggs
      • How to Press Tofu Without a Tofu Press
  • About Me
    • Collaborate With Me
    • Privacy Policy
menu icon
go to homepage
search icon
Homepage link
  • All Recipes
  • Instant Pot
  • Meal Prep
  • Airfryer
  • How To Tutorials
    • Facebook
    • Instagram
    • Pinterest
  • ×
    You are here: Home / Recipes / Sides / Potatoes au Gratin with Caramelized Onions and Roasted Garlic

    Potatoes au Gratin with Caramelized Onions and Roasted Garlic

    Posted: Nov 12, 2021 Last Modified: Nov 26, 2021 by Carmy · This post may contain affiliate links. As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.

    Jump to Recipe - Print Recipe

    If you’re looking for a delicious and flavourful side dish then this Potatoes au Gratin with Caramelized Onions and Roasted Garlic is it! Perfect for holidays or anytime you need a delicious side!

    Is there anything better than a potato-based side dish? Usually for the holidays, I keep it simple with mashed potatoes or baked potatoes but this time around, I felt like changing things up with this potatoes au gratin.

    Potatoes au gratin with caramelized onions and roasted garlic.

    Why You’ll Love This Side Dish

    • It’s a satisfying dish. I won’t lie to you, this is a heavy side since there’s potatoes, cheese, and a béchamel sauce but boy is it delicious.
    • It’s not the prettiest side dish but it’s a super tasty! I won’t say it’s an easy recipe per say as it’s a little time intensive, but it’s tasty enough that it’s worth the effort. This dish is adapted from Craving Home Cooked. It’s already a tasty dish to start but I add caramelized onions, roasted garlic, and infuse herb flavours into the béchamel sauce which require an extra hour of work. Luckily, you can caramelize the onions while the garlic is in the oven.
    • Components can be made ahead of time. Yes, I just said it takes an extra hour than your traditional potatoes au gratin but caramelized onions and roasted garlic can be made ahead of time so you break up the overall prep work.

    Ingredients You’ll Need

    Ingredients needed to make potatoes au gratin.
    • caramelized onion — to make caramelized onions, you’ll need 5 small onions, butter, and olive oil. You can see step by step photos in my how to make caramelized onion post.
    • roasted garlic — to make roasted garlic, you’ll need two heads of garlic as well as olive oil and a pinch of salt. You can see step by step photos in my how to roast garlic post. You can also roast garlic in an air fryer.
    • butter — unsalted butter is ideal as we are already adding salt to the béchamel sauce.
    • all-purpose flour — you’ll need flour to make the roux for the béchamel sauce.
    • chicken broth — I use low sodium chicken broth whenever possible.
    • milk — I use whole milk.
    • fresh herbs — I use rosemary and thyme.
    • salt and pepper — you can swap the pepper for white pepper if you want it to blend into the béchamel sauce.
    • Yukon gold — you can use Russet potatoes as well.
    • cheese — I use both cheddar and mozzarella sauce.
    • fresh thyme for garnish if desired
    • cooking spray

    How to Make Potatoes au Gratin with Caramelized Onions and Roasted Garlic

    • Close up of roasted garlic.
    • Caramelized onion on a plate with a spoon.

    Make the Roasted Garlic

    • Heat the oven to 400F.
    • Remove the paper-thin skin of the garlic. Trim the top ¼ inch off the top of the garlic bulb.
    • Place the heads of garlic onto a piece of tin foil and drizzle with olive oil, and sprinkle with salt. Tightly wrap the garlic in the foil.
    • Roast in the oven for 40 to 60 minutes. When cool to touch, remove the garlic cloves from the skin and set aside. You can squeeze the cloves out or simply peel the skin off. Set aside for later.

    Make the Caramelized Onions

    • Add the onions and sauté for 5 minutes or until the onions have softened.
    • Add the salt, if using, and reduce the heat to medium low and cook for 50 to 60 minutes. Stir the onions with a wooden spoon or spatula every few minutes, or until the onions are golden brown, and caramelized.
    • Set aside for later. Before adding to the baking dish, pat the onions with some paper towels to absorb any extra moisture.

    Make the Potatoes au Gratin

    • White sauce with herbs infused in a pot.
    • Sliced potatoes added to a baking dish.
    • In a small pot on medium low heat, melt the butter before adding the flour, bit by bit, and stir until evenly combined. Cook for a minute.
    • Slowly pour in the chicken broth and whisk until combined.
    • Slowly add in the milk, and whisk until combined.
    • Add the salt, pepper, and fresh herbs and allow fresh herbs to infuse for 2-3 minutes on low heat, stirring constantly. Do not let it come to a boil. Remove from heat and remove fresh herbs before setting aside.
    • Spray a 9×9 or 9×13 baking dish with non-stick spray.
    • White sauce added to the potatoes with caramelized onions and roasted garlic.
    • Cheese added to the baking dish.
    • Spread half of the sliced potatoes in an even layer on the bottom of the pan and top evenly with the caramelized onions, roasted garlic, and half of the béchamel sauce.
    • Top with half of the cheese.
    • More potatoes layered into the baking dish.
    • White sauce added to the baking dish.
    • Cheese added on top of the baking dish.
    • Baked potatoes au gratin.
    • Layer the rest of the sliced potatoes on top before adding the rest of the béchamel sauce and cheese.
    • Cover with tin foil and bake for bake for 45 minutes. Remove the tinfoil and bake for another 30 minutes, or until the potatoes are cooked through.
    • Let rest for 15 minutes before slicing and serving. Top with some fresh thyme if desired.
    Potatoes au gratin with caramelized onions and roasted garlic.

    Recipe Tips and Notes

    • I use a 9×9-inch baking dish but it goes right up to the top. If you don’t want to risk overflow, use a 9×13-inch baking dish.
    • I use a mandolin slicer to slice my potatoes evenly.
    • I always buy extra potatoes as I don’t run the entire potato through the mandolin slicers as I prefer using the larger slices of the middle portion of the potatoes (and protecting my fingers lol).
    • Resting before slicing gives the cheese time to set so the potatoes don’t fall apart as you serve them.
    • You can mash the roasted garlic into a paste and mix it into the béchamel sauce. I just like having little surprise bits of cloves when I take a bite out of the potatoes au gratin.
    • I highly recommend grating your own cheese instead of using a bag of pre-shredded cheese. The cheese melts much better as there isn’t an anti-clumping coating on cheese you shred from a block yourself. It’s super easy if you have a food processor as you can use the shredder blade and just run the block of cheese through it.
    A plate of potatoes au gratin with caramelized onions and roasted garlic.

    Make Ahead Tips

    • Make ahead: make the roasted garlic and caramelized onion up to 3 days ahead of time. Store it in an airtight container in the fridge.
    • Freezer: the potatoes’ texture may not be the same after freezing. If you’re ok with that, this potatoes au gratin can be frozen for up to 1 month after its been baked.
    What does potatoes au gratin mean?

    Potatoes au gratin or au gratin potatoes means “covered with bread crumbs or grated cheese and browned” according to Merriam-Webster.

    Do I peel the potatoes?

    For thin-skinned potatoes like Yukon Gold, I don’t peel the potatoes. Simply give them a good scrub and pat them dry before slicing. If you use russet potatoes, peel them before slicing as the skin is much thicker.

    Cheeses to use for potatoes au gratin?

    You can use any type of melty cheese such as gruyère, parmesan, smoky gouda, or spicy cheese for a kick of heat.

    What is the difference between scalloped and au gratin potatoes?

    According to Southern Living, potatoes au gratin are more decadent as they are made with lots of cheese in between the layers of potatoes and on top as well.

    Serving Ideas

    Here are a few dishes that go well with potatoes au gratin:

    • Turkey: try my Instant Pot turkey breasts and gravy or oven roasted turkey thighs.
    • Chicken: try my Dutch oven chicken, roasted chicken quarters, or crispy chicken drumsticks.
    • Sides: as these potatoes are heavy, I’d go with lighter side dishes such as maple Brussels sprouts, this silken tofu recipe, oven roasted beets, seasoned spinach, or asparagus.
    Potatoes au gratin with caramelized onions and roasted garlic.

    Potatoes au Gratin with Caramelized Onions and Roasted Garlic

    If you’re looking for a delicious and flavourful side dish then this Potatoes au Gratin with Caramelized Onions and Roasted Garlic is it! Perfect for holidays or anytime you need a delicious side!
    5 from 1 vote
    Print Rate
    Prep Time: 30 mins
    Cook Time: 2 hrs 15 mins
    Resting Time: 15 mins
    Total Time: 3 hrs
    Servings: 8 servings

    Ingredients

    For the Roasted Garlic

    • 4 to 5 heads of garlic
    • 4 to 5 tsp olive oil
    • 1 pinch salt

    For the Caramelized Onions

    • 5 small sweet onions, sliced
    • 1 tbsp butter, unsalted
    • 1 tbsp olive oil
    • pinch salt, optional

    For the Potatoes au Gratin

    • 3 tbsp butter unsalted
    • ¼ cup all-purpose flour
    • 1 cup chicken broth, low sodium
    • 2 cups milk
    • 1 tsp salt
    • ¼ tsp pepper
    • 5 sprigs fresh thyme
    • 5 sprigs fresh rosemary
    • 3 lbs Yukon gold, sliced into ⅛ inch rounds
    • 1½ cup sharp cheddar cheese, freshly shredded
    • 1 cup mozzarella, freshly shredded
    • cooking spray

    Instructions

    For the Roasted Garlic

    • Heat the oven to 400F.
    • Remove the paper-thin skin of the garlic.
    • Trim the top ¼ inch off the top of the garlic bulb.
    • Place the heads of garlic onto a piece of tin foil and drizzle with olive oil, and sprinkle with salt.
    • Tightly wrap the garlic in the foil.
    • Roast in the oven for 40 to 60 minutes.
    • When cool to touch, remove the garlic cloves from the skin and set aside. You can squeeze the cloves out or simply peel the skin off. Set aside.

    For the Caramelized Onions

    • Add the onions and sauté for 5 minutes or until the onions have softened.
    • Add the salt, if using, and reduce the heat to medium low and cook for 50 to 60 minutes. Stir the onions with a wooden spoon or spatula every few minutes, or until the onions are golden brown, and caramelized.

    For the Potatoes au Gratin

    • In a small pot on medium low heat, melt the butter before adding the flour, bit by bit, and stir until evenly combined. Cook for a minute.
    • Slowly pour in the chicken broth and whisk until combined.
    • Slowly add in the milk, and whisk until combined.
    • Add the salt, pepper, and fresh herbs and allow fresh herbs to infuse for 2-3 minutes on low heat, stirring constantly. Do not let it come to a boil. Remove from heat and remove fresh herbs before setting aside.
    • Spray a 9×9 or 9×13 baking dish with non-stick spray.
    • Spread half of the sliced potatoes in an even layer on the bottom of the pan and top evenly with the caramelized onions, roasted garlic, and half of the béchamel sauce. Top with half of the cheese.
    • Layer the rest of the sliced potatoes on top before adding the rest of the béchamel sauce and cheese.
    • Cover with tin foil and bake for bake for 45 minutes. Remove the tinfoil and bake for another 30 minutes, or until the potatoes are cooked through.
    • Let rest for 15 minutes before slicing and serving. Top with some fresh thyme if desired.

    Notes

    • You can mash the roasted garlic into a paste and mix it into the béchamel sauce. 
    • Recipe adapted from Craving Home Cooked.
    Tried this recipe?Did you make this recipe? I’m always so happy to hear about it! I’d love to see how it turned out. Tag me at @CarmysHungry on Instagram so I can see it! If you enjoyed the recipe, I’d really appreciate a comment with a 5 star rating! ♥

    Nutrition Per Serving

    Calories: 496kcal | Carbohydrates: 57g | Protein: 17g | Fat: 23g | Saturated Fat: 12g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 8g | Trans Fat: 1g | Cholesterol: 54mg | Sodium: 593mg | Potassium: 1167mg | Fiber: 6g | Sugar: 15g | Vitamin A: 619IU | Vitamin C: 49mg | Calcium: 386mg | Iron: 3mg
    Authour: Carmy
    Course: Side Dish
    Cuisine: American

    Other places to connect with me
    @carmyshungry on Instagram
    Facebook
    Shop my Amazon faves
    Email: [email protected]

    NEVER MISS A POST!

    Want a free downloadable shopping list and recipes for one week's meal prep (lunches and snacks)? Sign up now for updates and get your shopping list and recipes today!

    Reader Interactions

    Leave a Reply Cancel reply

    Your email address will not be published. Required fields are marked *

    Recipe Rating




    Primary Sidebar

    Carmy is a healthy-ish living blogger based in Toronto. Here you can find healthy-ish meal prep recipes, Instant Pot recipes, and lightened up family favourites! Follow along as she shares what she learns along the way!

    More about me →


    Click here
    if you’d like to collaborate with Carmy

    Popular

    • Gochujang Chicken Thighs (Grilled or Stovetop)
    • Hibachi Chicken with Fried Rice
    • Garlic Herb Butter Roasted Chicken in a Dutch Oven
    • How To Make Instant Pot Poached Eggs

    Footer

    ↑ back to top

    About

    • About Me
    • Privacy Policy
    • Work with Me

    Newsletter

    • Sign Up! for emails and updates

    Recipes

    • All Recipes
    • Meal Preps Recipes
    • Instant Pot Recipes

    Copyright © 2021 Carmy — Easy Healthy-ish Recipes