Reverse Sear Flat Iron Steak

A seasoned flat iron steak is cooking a grill grate.
This recipe is sponsored by Slap Yo' Daddy

Tender and flavorful flat iron steak is smoked, grilled, then served with mushroom mashed potatoes and a red wine sauce. This is a fancy meal that is great to impress guests at home, but is just as tasty when camping outdoors. To make the meal quick and easy, prepare the mashed potatoes up to a few days ahead of time.

We often think of grilling steak over high heat, then moving it to a cooler part of the grill to reach the right internal temperature. In the reverse sear method, the steak smokes on the cool side of the grill, getting to the perfect temperature, then is quickly charred on the hot side of the grill. This results in tender and perfectly-cooked meat, without burning the outside.

Flat iron steak, also known as top blade steak, is cut from the shoulder of the cow and packs a lot of flavor. A cheaper cut of meat than traditional steaks, flat iron is still very tender and quite tasty. If your butcher does not carry flat iron steak, flank steak and skirt steak are excellent substitutions.

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Sliced flat iron steak sprinkled with parsley rests atop mashed potatoes on a blue plate, with a bowl of red wine sauce on the side.
Flat iron steak is reverse seared then served with mushroom mashed potatoes and a red wine sauce for a tasty dinner.
A raw flat iron steak seasoned with rub rests on a white plate.
Before griling the flat iron steak, generously sprinkle it with the rub to marinate.
A small saucepan of red wine is simmering on the stove top.
A rich demi-glace is made by reducing red wine and stirring in cold butter to form an emulsion.
A seasoned flat iron steak is cooking a grill grate.
Start cooking the steak on the cooler part of the grill; once it reaches your desired temperature, char it on the hot side of the grill.

Reverse Sear Flat Iron Steak Recipe

This recipe is sponsored by Slap Yo’ Daddy.
A seasoned flat iron steak is cooking a grill grate.
Tender and flavorful flat iron steak is smoked, grilled, then served with mushroom mashed potatoes and a red wine sauce.
Preparation 10 minutes
Cook 45 minutes
Ready in 55 minutes
Servings 6
CourseMain Dish
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Steak – Smoking

Wine Butter Sauce

  • 2 cups semi-sweet red wine
  • 2 tablespoons unsalted butter, chilled
  • salt and pepper to taste

Mushroom Mashed Potatoes

  • 1 cup white mushrooms, minced
  • 2 tablespoons unsalted butter
  • 1 teaspoon minced garlic
  • 1 cup chicken stock
  • 2 cups cooked mashed potatoes
  • salt and white pepper to taste

Steak – Grilling

  • 2 tablespoons unsalted butter melted
  • 3 sprigs fresh rosemary

To Serve

  • 1 sprig parsley finely chopped


  • grill
  • pecan wood chunk


Steak – Smoking

  • In a bowl, mix together the beef rub and granulated garlic.
  • Brush both sides of the steak with vegetable oil.
  • Apply a medium coat of beef-garlic rub to both sides of the steak. Rest the steak in the fridge while you set the smoker.
  • Preheat the grill to 275 degrees F (135 degrees C) with a direct hot zone and an indirect cold zone. When hot, add a chunk of pecan wood.
  • Place the steak onto the preheated grill in the indirect zone away from the fire.
  • Smoke the steaks until the internal temperature is about 110 degrees F (43 degrees C), approximately an hour. While smoking prpeare the sauce and potatoes

Wine Butter Sauce

  • Heat the red wine in a saucepan over high heat to a boil. Continue to boil until reduced to about 2 tablespoons of syrupy red liquid. Lower the heat.
  • Cut the chilled butter into small pieces. Slowly stir into the wine syrup one piece at a time until the sauce becomes silky and thick enough to coat the back of a spoon. Season to taste with salt and pepper.
  • Remove from the heat and keep warm while you grill the steak.

Mushroom Mashed Potatoes

  • Sauté the minced white mushrooms with the butter and garlic over medium heat until the mushrooms release their juices, about 10 minutes.
  • Add a bit of chicken stock to cook the mushrooms to reduce them into a wet paste-like consistency. This will be about ¼ cup yield.
  • Mix the sautéed mushrooms with two cups of cooked mashed potatoes.
  • Add chicken stock, a tablespoon at a time, to get the mashed potatoes to the desired consistency.
  • Taste then add the salt and white pepper as needed. Keep warm and set aside.

Steak – Grilling

  • Move the steaks from the indirect zone to the direct zone to get a char.
  • Brush on the melted butter using a few rosemary sprigs tied together as a brush. Remove when medium rare, about 128 degrees F (53 degrees C) or the doneness you like.
  • Rest for 15 minutes.

To Serve

  • Brush the steak with some melted butter and a light sprinkle of beef rub as a finishing rub before slicing the steak diagonally against the grain.
  • Serve the flat iron steak slices on some of the mushroom mashed potatoes.
  • Drizzle the red wine sauce on the steak or serve on the side. Garnish with chopped parsley.

Nutritional Information

Calories: 544kcalCarbohydrates: 24gProtein: 25gFat: 32gSaturated Fat: 13gPolyunsaturated Fat: 4gMonounsaturated Fat: 11gTrans Fat: 1gCholesterol: 106mgSodium: 713mgPotassium: 866mgFiber: 2gSugar: 2gVitamin A: 406IUVitamin C: 8mgCalcium: 41mgIron: 4mg

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