These easy crockpot meatball subs are a hearty weeknight meal idea, made simple thanks to your slow cooker! Uses frozen meatballs in a chunky homemade marinara sauce, topped off with ooey-gooey melted mozzarella cheese...
Add the olive oil, crushed tomatoes, tomato paste, onions, water, garlic, Italian seasoning, salt and pepper, and sugar to a 5-qt.+ slow cooker insert. Stir well. Nestle the frozen meatballs in the sauce and cover.
Cook for 4 hours on high or 6 hours on low, until the sauce is bubbling and the meatballs are heated through.
Add desired number of meatballs to the sub rolls and top with Parmesan cheese. Alternatively, you can also top them with shredded mozzarella cheese. Then place them on a baking sheet under the broiler on high for 3-4 minutes until the cheese is melted and bubbly.
Recipe Notes
*Italian Seasoning This meatball subs recipe has been tested with my go-to brand of Italian seasoning. It is a coarser mix then most other Italian seasonings. If you use a brand that is more finely ground or powder-like, you may want to start with less than the recipe calls for and add more as needed.