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Flat Iron Steak Sandwich


Flat Iron Steak Sandwich

David Venable of QVC recommends cooking the steak for these sandwiches on either the grill or at the stove. Make a quick dipping sauce of mayonnaise, horseradish, Worcestershire, and Dijon for the sandwich.

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  • ½ Cup mayonnaise
  • 3 Tablespoons prepared horseradish
  • 3 Teaspoons salt
  • 1½ Teaspoon black pepper
  • 1 Teaspoon Dijon mustard
  • 1 Teaspoon Worcestershire sauce
  • 2 Tablespoons butter
  • 4 Cups sliced onions (¼-inch thick)
  • 2 Pounds flat iron steaks, at room temperature
  • 2 Tablespoons oil
  • 8 5- to 6-inch club rolls, split vertically ¾ the way through
  • 2½ Cups shredded Cheddar cheese


Preheat the oven to 350 degrees F.

Combine the mayonnaise, horseradish, ½ teaspoon salt, ¼ teaspoon pepper, the mustard, and Worcestershire sauce in a small bowl. Whisk until smooth and refrigerate until ready to serve.

Melt the butter in a medium skillet set over medium heat. Add the onions, ½ teaspoon salt, and ¼ teaspoon pepper to the pan. Sauté the onions until browned and caramelized, 15 to 20 minutes, stirring occasionally.

Sprinkle the steaks on both sides with the remaining 2 teaspoons of salt and 1 teaspoon of pepper. Heat the oil in a large oven-proof skillet over medium-high heat. Add the steaks to the pan and sear until browned, 4 to 5 minutes on each side. When second side is browned, place the skillet into the oven. After 5 minutes, flip the steaks and continue to cook until the internal temperature has reached 135 degrees F (medium-rare) or 140 degrees F (medium), 10 to 15 minutes. Remove the pan from the oven, cover the steaks with foil, and let them rest for 5 minutes.

While the steaks are resting, place the rolls on a baking sheet cut-side up, and divide the cheese among the rolls. Then divide the caramelized onions among the rolls. Place the rolls into the oven and bake until the cheese melts, 5 to 8 minutes.

When the steaks finish resting, transfer them to a cutting board and thinly slice against the grain. Divide the meat among the rolls and top with about 1 tablespoon of the horseradish sauce.