Pre-heat the oven to 375 degrees F. Combine the grated onion, eggs, garlic, torn bread, Parmesan cheese, beef, pork, salt and pepper together in a bowl and stir gently with a fork or with your hands. Shape the meatballs into 1 1/2 inch diameter balls if you want them small, and 2 1/2 inches for larger meatballs. Place them on a baking sheet. Bake the meatballs for 20-30 minutes (depending on their size) or until cooked through and lightly browned.