Set oven to 350F. Crack egg into a large mixing bowl and beat well with a fork. Add ground beef, breaking it apart as it is  added to the bowl Add remaining ingredients except tomato sauce and Mozzarella cheese. Mix to combine well. Don't compact the meat, and don't over mix, so meatballs are fluffy and light. Form meat into approximately 22 balls with hands or 1 1/2 inch cookie scoop. Set the meatballs on a baking sheet and cook 15 minutes.

While meatballs are in the oven, pour sauce into a skillet and place in the oven with the meatballs for the last 10 minutes of cooking, to warm sauce.  Remove both pans from oven and transfer meatballs to sauce. Return skillet to the oven and cook another 10 minutes. Remove skillet again and top with cheese. Return to oven to melt cheese. Set under the broiler to brown, but watch carefully. Serve immediately with garlic bread.