On medium-high heat, add in the olive oil to the Dutch oven, salt and brown the whole chicken, starting with breast side down then flipping it around 5-10 minutes or until the skin has turned golden brown.
Set aside the chicken and in the pot, add onions, garlic, and crushed red pepper flakes. Sauté until the onions have softened.
Add in the coconut milk and green curry paste and bring it to a boil. Add the chicken back in, breast side up, cover, and simmer on medium for 35-40 minutes.
Uncover the pot, add in the leeks, lime juice + zest, and green onions. Simmer for another 10-15 minutes or until the chicken has cooked through. The safe internal temperature for cooked chicken is 165° F (75° C)
Serve with your carb of choice. I serve with basmati rice.
Optional: before serving, to crisp up the chicken skin, I put the entire Dutch oven into the oven and broil for 1-3 minutes and add a bit more lime juice, a handful of basil, more green onions, and a sprinkle of the chili flakes.