Begin by heating the coconut oil in your large skillet over medium heat. Once the oil is hot, add the finely chopped yellow onion. Sauté for about 3-4 minutes, or until the onion becomes translucent and fragrant.
Next, add the chopped boneless skinless chicken breasts to the skillet. Cook for about 5-7 minutes, stirring occasionally, until the chicken is no longer pink.
Stir in the chopped red bell pepper and continue to cook for an additional 2-3 minutes. Then, add the panang curry paste. Mix well to coat the chicken and vegetables.
Add the first can of full-fat coconut milk. Pour it in and stir to combine everything. The creamy coconut milk will create a luscious base for your curry.
Mix in the peanut butter (or almond butter) and stir until well combined. Then, add the fish sauce and coconut sugar, if using. Taste your curry and season with sea salt as needed.
Bring the curry to a gentle simmer, then reduce the heat to low. Allow it to simmer for about 10-15 minutes, stirring occasionally.
Once your Thai Panang Curry has reached the desired thickness, taste and adjust any seasonings if necessary.
Serve your Thai Panang Curry over steamed jasmine rice or with warm naan bread. Garnish with fresh cilantro or chopped peanuts for an added crunch.