Guinness Marinated Flat Iron Steak
Remove flat iron steak from packaging and trim excess silver skin; place the flat iron in a 1-gallon size zip-top bag. Combine the ingredients for the marinade in a small bowl and pour over steak. Marinate for 1 hour.
Prepare charcoal grill for direct grilling at 500 degrees.
Prepare charcoal grill for direct grilling at 500 degrees. While grill is heating prepare Guinness Mushroom sauce: Melt butter in a sauce pan over medium heat. Add shallot and garlic and sauté for 2 minutes. Add sliced mushrooms and season with AP seasoning. Sauté for 2-3 minutes until mushrooms are tender. Add Worcestershire, soy, and balsamic reduce for 3-4 minutes; add Guinness and reduce volume by half (approx 5-7 minutes). Combine corn starch and cold water in a small bowl and whisk into sauce. Allow the mixture to reach a slight boil and remove from heat. Serve warm over steak.
Remove the flat iron steak from the marinade allowing excess moisture to drip back into the zip-top bag. Season the steak with Killer Hogs Steak Rub on all sides.
Place the steak on the grill and cook for 5 minutes. rotate the steak after 2.5 minutes to create grill marks. Repeat the same step for the opposite side for a total cook time of 10 minutes or until the steak reaches 125 internal temperature – medium-rare.
Rest the flat iron for 5-7 minutes before slicing and serve topped with Guinness Mushroom sauce.