Preheat oven to 350*. Melt butter in skillet over medium heat. Fry the zucchini in the butter til browned and slightly tender. Season and stir in marinara sauce. Cook and stir til sauce is heated.
Spoon generous amount of the mixture into each roll. Top with a handful of mozzarella. Close the rolls and wrap individually in foil.
Bake for 15 min. or til cheese is melted.