This is what I do when I make meatballs:
1 lb Italian sausage/ Italian seasoned ground beast
1 head garlic, minced
1 lb mozzarella grated or torn/ cut into 1/2" chunks
Mix the garlic well into the sausage of seasoned beast. Grab a 1" diameter hunk of beast, and poke a hole in it with your finger to the middle of the ball. Stuff one of your chunks of mozzarella or 2 tbsp grated mozz into the hole and seal her up, making sure there aren't any holes for the cheese to escape through. Saute' until meat is done.