In a bowl, combine the ingredients for the chicken meatballs.
1 pound ground chicken, 1/2 cup Italian style breadcrumbs, 1/4 cup whole milk, 1/4 cup shredded Parmesan cheese, 1 egg, 1 tsp minced garlic, 2 tablespoons fresh basil
Take a large spoonful of the mixture, and using your hands roll into a ball shape. You will want a total of 15 meatballs, 3 per sandwich.
Place on a 9x13" baking sheet covered with parchment paper.
Bake for 20 minutes.
Brush the inside of the bread wells with the balsamic vinaigrette.
Place three meatballs into the center of each bun.
Sprinkle each sandwich with shredded mozzarella cheese.
1 cup shredded mozzarella cheese
Place back into the oven and bake for 10 minutes.