4 (6-inch) hoagie buns, hollowed
2 tbsp. olive oil
Mozzarella cheese
meatballs in fresh tomato sauce
tomato sauce
grated Parmesan

Preheat oven to 450°F. Prepare buns by shaving a thin layer off the top of each roll. Remove some of the bready interior so you're left with a "submarine". Brush inside of hollowed-out buns with olive oil. Fill bottom of each bun with Mozzarella and place them on a baking sheet.

Bake until buns are lightly browned and cheese melts. Fill subs with hot tomato sauce, then 2 to 3 meatballs. Top subs with more sauce, then sprinkle with cheese.