If using uncooked chicken, heat about a tablespoon of oil over medium heat in a large skillet. Add the chicken breasts and cook 6-7 minutes without moving them. Flip the chicken breasts and cook for another 6-7 minutes, until cooked through.
Spread half of the sauce on the bottom of a large skillet. Arrange the cooked chicken breasts inside the skillet. Drizzle the rest of the sauce on top of the chicken.
Slice the mozzarella cheese and lay it on top of the grilled chicken. Place your pepperoni and any other toppings you're using on top of the cheese.
Cover the skillet and cook on medium-low for about 6-7 minutes or until the sauce is bubbling and the cheese is melty. Optionally, you can finish it under the broiler for about 2 minutes. Sprinkle with basil & serve.