Preheat The Oven To 350 Degrees F (175 Degrees C). Melt Butter In A Skillet Over Medium Heat. Fry The Zucchini In Butter Until Browned And Slightly Tender. Season With Red Pepper Flakes, Salt And Pepper, And Stir In The Marinara Sauce. Cook And Stir Until Sauce Is Heated. Spoon A Generous Amount Of The Zucchini Mixture Into Each Sandwich Roll. Top With A Handful Of Shredded Mozzarella. Close The Rolls, And Wrap Individually In Aluminum Foil.