In a small saucepan, combine the meatballs with the spaghetti sauce and simmer over low heat until just warmed through. Alternatively, place meatballs and sauce in a microwave-safe dish, cover with a damp paper towel, and microwave in 1-minute intervals, until warmed through.
In a small bowl, combine olive oil with the garlic and oregano.
Place the buns on a baking sheet and brush the opened sides of the buns with the olive oil mixture. Bake for 5 minutes, or until just lightly browned.
Remove the buns from the oven and place 2 slices of provolone cheese on each bun, slightly overlapping if needed, to cover the opened surface. Top each bun with 3 large meatballs. Add an additional slice or two of cheese on top of the meatballs to cover the meatballs. You essentially want the meatballs to be enveloped in cheese on all sides.
Return to the oven and bake for 5-7 minutes or until the cheese is melted.
Close the sandwich and serve meatball subs immediately.
Notes
Meatballs: Use any Italian-flavored meatballs you like for this recipe. Homemade meatballs are my favorite! If using smaller meatballs, use 4 meatballs per sub.Spaghetti Sauce: Use your favorite, well-seasoned spaghetti sauce for the best flavor. Cheese: Thinly sliced provolone is best, but thicker sliced provolone or mozzarella can be used. Evenly shredded will work -- just be generous.