Sear the Chicken
In a large, deep skillet, heat the coconut oil over medium heat. Season the chicken with ground coriander, salt, and pepper. Pat the chicken dry with paper towels to ensure a crisp sear. Place the chicken in the skillet, skin-side down, and cook for about 10 minutes until the skin begins to crisp. Increase the heat to medium-high and continue cooking, without flipping, for an additional 4 to 5 minutes until the skin is deeply browned. Transfer the chicken to a plate, keeping it skin-side up.
Sauté Aromatics
Lower the heat to medium-low and add the sliced scallions, chopped lemongrass, ginger, garlic, turmeric, and optional makrut lime leaves to the skillet. Stir frequently, cooking for 6 to 8 minutes until the aromatics become tender and fragrant.
Simmer the Chicken
Pour in the chicken stock and coconut milk, stirring to combine. Bring the mixture to a boil over high heat. Return the chicken, skin-side up, to the skillet, reduce the heat to medium-low, and simmer for 20 to 25 minutes for thighs, or 30 to 35 minutes for legs, until the chicken reaches an internal temperature of 165°F (75°C), or when the juices run clear when pierced.
Finish the Sauce
Once the chicken is cooked through, transfer it to a plate. Whisk the sauce in the skillet to emulsify, adjusting the seasoning with salt and pepper as needed. Add the sliced peppers to the skillet and cook for 2 to 3 minutes until they are just tender. Return the chicken to the skillet, browning it side up, and garnish with small sprigs of cilantro.
Serve
Serve the chicken with a side of rice or noodles, and offer extra cilantro at the table for those who desire additional fresh seasoning.