These slow cooker meatball subs are the ultimate comfort food with tender, flavorful meatballs and bubbly melted cheese. Perfect for feeding a crowd with minimal effort.
In a large bowl, combine the ground beef, ground italian sausage, italian breadcrumbs, grated parmesan, egg, minced garlic, italian seasoning, salt, and black pepper. Mix gently until just combined. Roll the mixture into about 20 meatballs, roughly 1.5 inches each.
Pour about half of the marinara sauce into the bottom of the slow cooker. Arrange the meatballs in a single layer on top of the sauce.
Pour the remaining marinara sauce over the meatballs and sprinkle with red pepper flakes.
Cover and cook on low for 6 to 7 hours or on high for 3 to 4 hours, until the meatballs are cooked through and tender.
Load 3 to 4 meatballs into each toasted sub roll and spoon extra marinara sauce from the slow cooker over the top.
Top each sub with a generous handful of shredded mozzarella cheese. Place under the broiler for 1 to 2 minutes until the cheese is melted and bubbly.