In a bowl, marinade the chicken fillets with brown sugar, salt, pepper, garlic powder, paprika, annatto powder, soy sauce, ketchup, and pineapple juice.

Mix well. Place in airtight containers. You can keep these in different containers to fit your meal plan / serving / or if you plan to freeze these to sell. If not, simply marinade overnight in the fridge.

Douse with the leftover marinade. Marinate for at least 8 hours or overnight.

In a pan that's hot enough. Pan-fry the chicken, pouring a bit of the marinade. You want to cook these in 1 layer at a time. Avoid overcrowding.

Flip occasionally. Once cooked, the sauce has mostly dried up. Pour in a bit of oil. Cook until both sides have charred. Take these out and enjoy them with rice, pickles, eggs, or tomatoes on the side.