Preheat a grill on medium heat.
Lightly coat the outsides of the peppers with the olive oil. Flip the peppers over so they make little bowls, spoon a little marinara sauce in the middle of each and cover in cheese. Add toppings as desired.
Place on the grill until the cheese is melted and the undersides are tender, 10 to 15 minutes.
Recipe courtesy of Good to Know