Heat the olive oil in a large skillet on medium-high heat and then add in the onions. Let the onions sweat it out for 2-3 minutes before adding in the oregano, red chili flakes, salt, and pepper.
Give it a stir and let it cook for another minute before adding in your garlic.
Next, add in the ground beef and let it brown, making sure to break up the meat with your wooden spoon for 8-9 minutes.
Add in the mushrooms and continue to stir for another minute, making sure the mushroom is well incorporated with the beef.
Stir in the tomato paste and then add in the canned whole tomatoes, breaking up the tomatoes in the skillet as you stir.
Add in your brown lentils with a cup of water and bring the whole skillet to a boil before turning down the heat. Simmer for 15-20 minutes or until the lentils are cooked through, stirring occasionally.
Once done, in a mason jar, layer in the bolognese, pine nuts, optional cheese, and cooked pasta. Store for up to 5-6 days in the fridge.