Two fresh 4 oz, choice 81/19 beef patties smashed onto a hot griddle to create a crispy, caramelized crust, then topped with sautéed mushrooms and melted Swiss cheese. Served with crisp lettuce and a touch of creamy peppercorn Shack Sauce, this burger delivers juicy flavor with earthy depth in every bite. Hearty, indulgent, and crafted for true comfort food lovers.