1. Preheat oven to broil. Microwave meatless meatballs for 2 minutes. In a large sauce pan, pour in marinara sauce then add in warm meat balls and stir to submerge them.
2. Cover and let simmer on medium-low for 10 minutes, stirring gently occasionally. Lay out both sides of cut roll on a cookie sheet.
3. Arrange spinach (and optional basil) on 1 side of each roll. Scoop finished balls with extra sauce on spinach side.
4. Top with cheese. Broil for about 3 minutes, or until bread is toasty and cheese is melted. The meatballs won't be very firm, but will be very delicious.
Serve with lots of napkins!
Source of recipe: I wrote this.