Steak Sandwich

Season the steak with salt, pepper, and garlic salt. Grill to your desired temperature. For the onions. Add the sliced onion and mushrooms, the butter, Worcestershire, red pepper flakes, salt, pepper, and butter to a pan. Slowly cook until golden brown. For the aioli, mix the mayo, lemon juice, minced garlic, and pepper. Toast your bread. Build: Bread, aioli, steak, onions, arugula, aioli, bread.