For this recipe, I put an Irish spin on a flat iron steak for St. Patrick’s Day. It's a Flat Iron Steak marinated in Guinness Beer, served with smoked potatoes and a Guinness Mushroom Sauce. Guinness Flat Iron Steak Marinade: - 1 Flat Iron Steak – 1.5lbs - 1 Tablespoon Killer Hogs Steak Rub - Guinness Flat Iron Steak Marinade: - 12oz Guinness Stout Beer - 2oz Worcestershire Sauce - 2oz Soy Sauce - 1 teaspoon Killer Hogs BBQ AP Seasoning Combine ingredients in a small bowl and use as a marinade f