Open Hoagie Roll so that it lays flat (keeping top and bottom buns attached). Butter the flat side of the roll.
Grill, butter-side down, or toast in oven or toaster oven until lightly toasted and golden.
Spread ketchup onto top of Hoagie Roll. Top with thinly sliced tomatoes, a sprinkle of oregano, sliced onions, American cheese, and Provolone cheese. Top with a sprinkle of Parmesan.
Broil for 2-3 minutes or until cheese is melted, bubbly, and golden-brown.
Serve open-faced; enjoy one of two ways: open with two halves or closed as a sandwich.
Recipe courtesy of Anita (Martin) Riblet