To make the meatballs, combine the ground meat, breadcrumbs, oregano, onion, egg, garlic, salt, and pepper in a large bowl and mix the ingredients together thoroughly with your hands.
Take a portion of the ground meat mixture and form a round, flat "plate" out of it. Place a piece of mozzarella in the middle, wrap the meat around it, and shape into a ball. Repeat this until you have 12 small, stuffed meatballs in front of you.
Fry the meatballs on all sides in plenty of oil and once they have browned, add the tomato sauce. Let the dish simmer for five minutes and then pour into a casserole dish.
In a separate bowl, add the salt, parsley, and garlic to the softened butter and mix well. Brush the finished spread on the baguette slices.
Line the inner edges of the casserole dish with the baguette slices so that they partially sink into the sauce. The buttered side of each slice should face inwards.
Sprinkle the shredded cheese over the stuffed meatballs and bake at 350°F for 20 minutes or until golden brown.
