Preheat the oven to 400°F
Pound chicken breasts to an even thickness
Season both sides with salt and pepper
Cut a pocket into each chicken breast
Fill with desired stuffing
Secure openings with toothpicks if needed
Place chicken in a greased baking dish or on a lined baking sheet
Brush with oil or melted butter
Season the outside with additional spices if desired
Bake for 25 to 35 minutes
Check that the internal temperature reaches 165°F
Let rest for 5 minutes
Remove toothpicks before serving