1 large red onion, cut into thin wedges
2 - 12 oz packages of frozen cooked Italian meatballs
1 - 24 to 26 oz jar marinara or pasta sauce
1 tbsp balsamic vinegar
1/2 tsp crushed red pepper
6 slices provolone cheese - quartered
Roma tomatoes, sliced
24 cocktail buns
Place onion wedges in a crock pot. Place meatballs on top of the onion.
Combine marinara, vinegar, red pepper and pour over meatballs.
Cover and cook on low for 4 to 5 hours (2 to 2 1/2 on high)
Place tomato and provolone cheese on bun. Add meatball. You can add a toothpick to keep it all together.
