6 ounces mozzarella or provolone cheese, shredded or thinly sliced
1 cup fresh arugula
In medium saucepan over medium-high heat, combine tomato sauce and meatballs. Bring to boil; reduce and simmer, covered. Cook 15 – 18 minutes, or until meatballs are heated through.
Heat broiler to HIGH.
Divide meatballs and sauce evenly among rolls. Top with cheese. Place on large rimmed baking sheet. Broil 2 to 3 minutes, or until cheese is melted and bubbly. Top sandwiches with arugula and serve at once