Starting at the top of the thickest portion, using a paring knife, cut a 2"-x-4" pocket into the chicken breasts.
Stuff with the filling combination of your choice, dividing evenly.
Season with salt and pepper.
Heat 1 tablespoon olive oil in a large skillet over medium heat. Cook until an instant-read thermometer inserted in the thickest portion reaches 165 degrees F, 6 to 7 minutes per side.