Broiled Flat Iron Steak Recipe

A flat iron steak is, as its name implies, flat, or as recipe developer Molly Madigan Pisula describes it, "fairly thin." She says this allows such a steak to cook in just a few minutes under the broiler, which can make for a great dinner in a hurry as long as you have a few quick and easy sides ready to go. Pisula does note, though, that if your steak is in excess of ½-inch thick, "you will need to add a little time to the broiling time estimates."

This steak isn't just broiled — first it's marinated in a combination of soy sauce, balsamic vinegar, and a few other ingredients. Pisula points out that the balsamic vinegar "adds flavor, helps tenderize the steak, and also adds a little more sugar content which helps the steak brown nicely and char in spots on the outside." Vinegar is often used in meat marinades, particularly for beef, as its acidity helps to break down muscle tissue. That is particularly helpful with this cut of meat as flat iron steaks can be kind of tough. Pisula also notes that balsamic vinegar "is really delicious," which is a good quality for a marinade to have.

Gather the ingredients for the broiled flat iron steak recipe

The main thing you need to cook this dish is a 12 to 16-ounce flat iron steak. For the marinade, you'll be using balsamic vinegar, soy sauce, brown sugar, garlic powder, and vegetable oil, while green onions do double duty as part of the marinade and as a garnish for the finished steak.

Marinate the steak

Cut the green onions into thin slices, then mix half of them with the vinegar, soy sauce, sugar, garlic powder, and oil. Use this mixture to marinate the steak in the refrigerator for 4 to 24 hours — Pisula uses a ziploc bag to do the job. She cautions, "Don't skimp on the marinating," explaining that this is necessary to both tenderize and flavor the steak.

Broil the steak

Once the steak is done, prep the broiler by making sure the top oven rack is just 4 to 6 inches below the heat element. Pisula says it makes a difference how close the pan is to the heat, telling us, "Too close, and the steak will burn. Too far, and it won't cook as quickly and won't have a nice char on the outside." If you have a broiler pan, line it with foil to help with cleanup. Pisula says a broiler pan isn't absolutely necessary and a sheet pan will work. If you're using the latter, she advises draining the steak well. Pisula says, "Extra marinade will easily burn," and a sheet pan doesn't have grates for it to drip down through.

Take the steak and let the excess marinade drip off, then put it on the pan and sprinkle it with salt and pepper on both sides. Broil it for 3 to 4 minutes on one side, then flip it and cook it for 3 to 4 minutes on the other. 3 minutes should yield a steak that's medium-rare, while 3 ½ minutes will yield medium and 4 will be closer to well-done.

Slice and garnish the steak

After the steak is done cooking, let it rest for 10 minutes, then slice it diagonally across the grain — Pisula says, "I recommend using a large serrated knife, like a bread knife, to slice the steak." Once the steak is sliced, you can sprinkle it with the rest of the green onions to make it look pretty.

Broiled Flat Iron Steak Recipe
5 from 24 ratings
Learn how to make this delicious steak that's marinated to perfection before being cooked quickly and easily in the broiler.
Prep Time
Cook Time
sliced steak on white plate
Total time: 4 hours, 12 minutes
  • 2 green onions
  • ¼ cup soy sauce
  • 2 tablespoons balsamic vinegar
  • 2 tablespoons brown sugar
  • 1 teaspoon garlic powder
  • ½ cup vegetable oil
  • 16-ounce flat iron steak
  • Salt
  • Pepper
  1. Slice the green onions.
  2. Combine the oil, soy sauce, vinegar, sugar, and garlic powder with half of the chopped onions.
  3. Use this mixture to marinate the steak in the refrigerator in a Ziploc-type bag for 4 to 24 hours.
  4. Situate the oven rack 4 to 6 inches below the heating element and set the oven to broil.
  5. Line the broiler pan with foil to make for easier cleanup.
  6. Let the excess marinade drip off the steak, then put the steak on the pan and season it with salt and pepper on both sides.
  7. Broil the steak for 3 to 4 minutes, then flip and broil for 3 to 4 more minutes.
  8. Let steak rest for 10 minutes.
  9. Slice steak diagonally across the grain and garnish it with the rest of the green onions.
Calories per Serving 918
Total Fat 74.3 g
Saturated Fat 11.1 g
Trans Fat 1.2 g
Cholesterol 154.2 mg
Total Carbohydrates 16.1 g
Dietary Fiber 1.1 g
Total Sugars 11.7 g
Sodium 1,944.4 mg
Protein 48.8 g
The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.
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