INGREDIENTS
1
Red onion cut into thin wedges (1 1/2 cups)
4
Roma tomatoes
1 tbsp
Balsamic vinegar
1
jar Marinara or pasta sauce
1/2 tsp
Red pepper
24
Cocktail buns
6
slices Provolone cheese
24
2 12 ounce package frozen cooked italian meatballs, frozen cooked