Step 1

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.

Step 2

Nestle the frozen meatballs in the sauce and cover.

Step 3

Cook for 4 hours on high or 6 hours on low, until the sauce is bubbling and the meatballs are heated through.

Step 4

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.