Add ground beef, ground pork, diced onion, bread crumbs, red pepper, oregano, 1 tbsp parsley, 1 tsp minced garlic, and the egg to a large mixing bowl.
Use your hands (preferably with gloves) to mix together until well combined. Shape meat mixture into golf ball-sized balls.
Place a cast-iron skillet or pan over medium-high heat.
Cook the meatballs, turning to cook each side for about 5 minutes or until browned on all sides, about 15-20 minutes.
Preheat the oven to 350°F
Place the soft rolls in a greased casserole dish.
Use a knife to cut a rectangle in the center of each roll, then press down on the inside to make a boat.
Mix together the melted butter, 1 tsp minced garlic, and 1 tbsp of parsley.
Use a brush to coat the rolls with the garlic butter.
Bake for 5 minutes to toast the bread and remove from the oven.
While the garlic bread is toasting, make the marinara sauce. Add all ingredients to a small saucepan and simmer for 10 minutes. (skip if using jarred sauce)
Put two slices of mozzarella into the rolls. Then add 2-3 spoonfuls of the marinara to the top of the cheese. Put three meatballs into each garlic bread boat, then cover the meatballs with marinara sauce. Add 1 more slice of cheese, cut in half to cover the meatballs.
Place in the oven and bake for 25 minutes. Remove from the oven and top with shredded parmesan.
Enjoy!