New Jersey Pork Roll Meatball Sub

Name: New Jersey Pork Roll Meatball Sub
Ingredients: 2 tbsp. olive oil; 1 tbsp. unsalted butter; 2 garlic cloves, finely chopped; 1 medium yellow onion, finely chopped; 1 tbsp. tomato paste; 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