1. Preheat oven to 350 degrees. Brush inside of split hoagies with melted butter. Lay buns open face on baking sheet and bake until lightly toasted.
2. Remove from oven and place shredded beef on bottom buns and sliced cheese on top buns. Bake open faced until beef is heated through and cheese is melted. Drizzle bottom half with reserved cooking liquid, garnish with banana peppers and giardiniera and serve.