Ground meats, bacon, onions, Parmesan, garlic and herbs in large bowl just until blended.
Bread crumbs, salt and pepper in separate bowl until blended. Gradually add milk, mixing well after each addition. Add eggs; mix well. Add to meat mixture; mix lightly.
Into 18 (115-g) meatballs (or into 9 meatballs for trial recipe). Use rounded handle of wooden spoon to poke hole into centre of each meatball. Place 15 g cheese mixture in each hole; re-roll meatball to completely enclose cheese mixture.
Half the oil (or all the oil for trial recipe) in large deep skillet on medium-high heat. Add half the meatballs (or all the meatballs for trial recipe); cook until evenly browned on all sides, turning occasionally. Transfer to 13x9-inch (3-L) baking dish (or to 11x7-inch [2-L] baking dish for trial recipe) with slotted spoon.
To cook remaining meatballs, adding remaining oil if necessary. Top meatballs with pizza sauce.
In 350ºF standard oven 45 min. or until done (165ºF).