Place a rack in the center of your oven and preheat the oven to 375°F. Season the chicken with salt and black pepper.
Melt the coconut oil over medium-high heat in a large, ovenproof skillet. Add the chicken and sear on both sides until deeply golden brown. Transfer to a plate.
Reduce the heat to medium-low. Add the bell pepper, leek, garlic, and ginger, and stir to combine. Cook for 2 minutes, until slightly softened.
Stir in the curry paste. Cook for 5 additional minutes, stirring often. Slowly pour in the coconut milk while stirring to combine. Return the reserved chicken to the skillet.
Place the skillet in the oven and bake for 25 minutes. The chicken will be fully cooked when a thermometer inserted in the thickest part of the chicken registers 165°F, and the juices run clear. (Note: Smaller chicken breasts may be done closer to the 15-minute mark.)
Top with cilantro. Serve with rice, spooning lots of the yummy curry coconut milk sauce over the top.
Notes
TO STORE: Leftovers may be kept in the refrigerator for up to 4 days.
TO REHEAT: Warm gently on the stovetop in a saucepan or wok until steaming. Alternatively, you can also microwave until heated through in a microwave-safe container.
TO FREEZE: I do not recommend freezing, as I have not had the best luck freezing sauces with a coconut milk base.