1 (28-ounce) can whole peeled tomatoes, crushed by hand
1 tbsp. sugar
Kosher salt and freshly ground black pepper
1/3 cup breadcrumbs
1/3 cup milk
1 lb. ground beef
8 oz. pork roll, cut into 1/4-inch pieces
2 1/2 tbsp. finely chopped parsley
1 red onion, grated
3 tbsp. olive oil
4 (5-oz.) hoagie/hero rolls, split lengthwise
8 slices provolone cheese
Instructions
Heat olive oil and butter in a 4-quart saucepan over medium-high; add garlic and finely chopped onion and cook until soft, about 6 minutes. Add tomato paste and cook 2 minutes more, then add tomatoes, sugar, salt, and pepper; cook until thick, 15-18 minutes. Keep marinara sauce warm.
Heat the oven to broil. Soak the breadcrumbs in the milk in a large bowl for 1 minute. Add the beef, pork roll, parsley, grated onion, salt, and pepper and mix thoroughly to combine. Using wet hands, form the mixture into 12 balls. Place on a baking sheet and drizzle with the olive oil. Cook the meatballs until golden, 8 to 10 minutes. Remove from oven, add to saucepan with marinara sauce, and toss lightly to coat.
Place bread on baking sheet and spread some sauce on either side. Top each with 3 meatballs and 2 slices of cheese. Cook until the cheese is golden and bubbling, about 2 minutes.