Slow Cooker Meatball Subs

Ingredients:
1 pound package frozen pre-cooked meatballs
1 jar (26 ounces) spaghetti sauce
1 to 2 cups shredded mozzarella cheese
4 sub sandwich rolls

Directions:
Combine meatballs and spaghetti sauce in crockpot. Cook on low for 3-5 hours or until heated through. Serve on meatballs submarine sandwich buns. Top with cheese. Heat subs in the oven to toast buns and melt cheese if desired.