Prepare 10 Sister Schubert’s® Dinner Yeast Rolls according to package directions. Split the rolls. Tear two rolls into pieces and reserve remaining 8 rolls.
For the meatballs, preheat oven to 375°. Line a sheet pan with parchment paper or aluminum foil. In a large mixing bowl, combine egg, milk, salt, herb blend and pepper. Add the 2 torn rolls and mash together. Add the ground beef and onions and mix well.
Form 16 to 20 small meatballs by using an ice cream scoop or a spoon and transfer to prepared pan. Bake 15 to 18 minutes or until the meatballs are thoroughly cooked.
Place marinara sauce in a saucepan and bring to a simmer, add cooked meatballs and Parmesan cheese and stir.
To assemble sandwiches: Place 2 meatballs inside each roll and top with mozzarella cheese. Place sandwiches on a baking sheet and place in the oven for 2 to 3 minutes or until the cheese melts. Serve hot.