This is so amazingly good and if you make the lighter version it's only 343 calories per serving! The whole family loves this! It tastes like a meatball sub but serves up a little like lasagna. Serve with a tossed salad and some fresh fruit and you've got a great meal!
Preheat oven to 400 degrees F. Line a shallow pan with foil; coat foil lightly with nonstick spray.
In a bowl, combine onion, bread crumbs, parmesan cheese, ground beef or turkey, and ground flax, if desired. Mix well and shape into 1 inch balls; place on prepared pan leaving a little space between each one. Bake at 400 degrees F for 15-20 min or until no longer pink.
Lightly coat a 13x9 baking dish with nonstick spray. Arrange Italian bread in a single layer in dish (I like to open the bread up like a sub and cut to fit in dish but however you'd like.) NOTE** All the bread may not fit in dish- that's ok.
In a separate bowl, combine cream cheese, mayo, Italian seasoning and black pepper. Blend until smooth and well combined. Spread over bread in dish. Sprinkle 1/4 of the mozzarella cheese onto cream cheese mixture on bread.
In a separate bowl, combine sauce, water and garlic; add the meatballs. Pour over cheese mixture. Sprinkle with remaining mozzarella.
Bake, uncovered in a 350 degree oven for 30 minutes or until heated through and cheese is melted. Serve hot.