Grilled Flat Iron Steak Recipe

Trim and prep

Pat the flat iron steak dry with paper towels. Trim any large pieces of silver skin or excess fat so the steak lays flat and cooks evenly (leave a little fat for flavor).

Make marinade

In a shallow dish or zip-top bag combine the olive oil, soy sauce, Worcestershire sauce, lemon juice, minced garlic (finely minced or pressed), black pepper, kosher salt, smoked paprika, and thyme. Whisk or shake to combine.

Marinate

Add the steak to the dish or bag and turn to coat thoroughly. Marinate in the refrigerator for at least 30 minutes and up to 4 hours. If short on time, 30–45 minutes still imparts good flavor. Remove the steak from the fridge 20–30 minutes before grilling to bring it closer to room temperature for even cooking.

Preheat grill

Preheat a gas or charcoal grill to high heat (about 450–550°F / 230–290°C). Clean and oil the grates well so the steak releases easily. If using a cast-iron grill pan, heat it over high heat on the stovetop until very hot.

Season before grilling

Lightly brush off excess marinade from the steak and discard used marinade. Pat the steak dry again with paper towels if very wet. Lightly brush with 1 teaspoon olive oil and sprinkle a small additional pinch of salt and pepper if desired.

Grill the steak

Place the steak on the hottest part of the grill. For a 1‑inch (approx.) flat iron steak: Grill 3–4 minutes per side for medium-rare (internal temp 130–135°F / 54–57°C), 4–5 minutes per side for medium (140–145°F / 60–63°C). Use tongs to flip only once. If the steak is thicker or thinner adjust time by 1–2 minutes per side. If cross-hatch marks are desired, rotate the steak 45 degrees halfway through each side's cooking time.

Check temperature

Use an instant-read thermometer inserted into the thickest part of the steak to confirm doneness: 125°F for rare, 130–135°F for medium-rare, 140–145°F for medium. Remove from grill when the steak is 5°F (about 3°C) below the target final temp because it will carry over cook while resting.

Rest the steak

Transfer the steak to a cutting board and tent loosely with foil. Let rest 7–10 minutes to allow juices to redistribute.

Finish with butter and herbs

While the steak rests, place the optional butter on top so it melts into the meat. Sprinkle chopped parsley over the steak for freshness.

Slice and serve

Slice the steak thinly across the grain against the muscle fibers to maximize tenderness. Arrange slices on a warmed plate. Serve with lemon wedges to squeeze over the meat and any preferred sides.