Mix meat, Parmesan, parsley, egg and half the garlic just until blended. Shape into 12 (1-1/2 -inch) meatballs; place on foil-covered rimmed baking sheet sprayed with cooking spray. Bake 15 min. or until done (160ºF).
Meanwhile, heat oil in large skillet on medium-high heat. Add onions; cook 3 min. or until crisp-tender, stirring frequently. Stir in remaining garlic; cook 1 min. Add tomatoes, tomato sauce and oregano; stir. Bring to boil; simmer on medium-low heat 10 min., stirring occasionally.
Separate bun tops and bottoms; place, cut sides up, on separate baking sheet. Spread bottom half of each bun with about 1 Tbsp. sauce; top with meatball. Spoon remaining sauce over meatballs. Top with mozzarella; bake 5 min. or until melted. Cover with tops of buns.
For Italian-flavored meatballs, prepare using ground pork and adding 1/2 tsp. fennel seed to the meat mixture before shaping into balls and baking as directed.
Calories From Fat
% Daily Value*
Total Fat 10g
Saturated Fat 3.5g
Trans Fat 0g
Total Carbohydrates 23g
Dietary Fibers 2g
* Percent Daily Values are based on a 2,000 calorie diet.
* Nutrition information is estimated based on the ingredients and cooking instructions as described in each recipe and is intended to be used for informational purposes only. Please note that nutrition details may vary based on methods of preparation, origin and freshness of ingredients used.