Pan-Seared Flat Iron Steak

This pan-seared flat iron steak has a deeply browned crust and a juicy, tender center. It’s dry-brined instead of marinated, cooked entirely in a skillet, and finished with garlic-herb compound butter for a rich, buttery finish with plenty of garlic and fresh herbs.

Flat iron steak is the second most tender cut of beef, right behind filet mignon. It has good marbling, plenty of beefy flavor, and cooks especially well over high heat, making it a great choice for pan-searing.

Ingredients You’ll Need

For the steak:

• Flat iron steak: Choose a steak that’s about 1 inch (2.5 cm) thick, preferably a little thicker. The extra thickness gives you more time to build a good crust before the center reaches your target pull temperature. You can buy pre-cut flat iron steaks, usually around 12 oz (340 g) each, or buy a whole flat iron muscle and cut it into smaller pieces that fit more easily in the skillet.
• Salt: For dry-brining, use about 1% of the steak’s weight in salt. For a 12 oz (340 g) steak, that’s about 3.4 g (0.12 oz). I prefer kosher salt because the larger crystals are easier to distribute evenly, but table salt works just fine. Since different salts vary quite a bit in crystal size, weighing the salt is the most reliable way to get consistent results. Once you’re familiar with the salt you use, you can eyeball it. I’ve included approximate teaspoon measurements for a few common salts in the recipe below.
• Oil: Use a neutral oil that can handle high heat. I usually use refined avocado oil, but refined olive oil, refined high-oleic safflower oil, refined high-oleic canola oil, refined canola oil, or refined peanut oil work well. Ghee (clarified butter) is another good option. Don’t use regular butter for searing because it burns quickly over high heat.

For the garlic-herb compound butter:

This makes enough compound butter for 2 flat iron steaks.

• Butter: 4 tablespoons (1/2 stick; 56 g) of good-quality unsalted butter. Use real butter, not margarine.
• Garlic: 2 cloves fresh garlic, finely minced or pressed.
• Salt and black pepper: Start with a generous pinch of each, about 1/8 teaspoon, then taste and add more if needed.
• Rosemary: 1/2 tablespoon finely chopped fresh rosemary or 1/2 teaspoon dried. If using fresh rosemary, chop it very finely so there are no tough, woody pieces in the butter.
• Parsley: 1/2 tablespoon finely chopped fresh parsley or 1/2 teaspoon dried.

Tools You’ll Need

• Wire rack and baking sheet: This is the setup I use for dry-brining. The rack keeps the steak elevated so air can move around it, so the surface dries evenly, while the baking sheet catches any drips.
• Heavy skillet: I prefer a cast-iron skillet for searing because it holds heat well and helps the steak develop a really deep crust. A carbon-steel or heavy stainless-steel skillet will also work. Don’t use a nonstick skillet for high-heat searing.
• Long-handled tongs: These make it easier to flip and move the steak without getting too close to the hot pan or splattering oil.
• Meat thermometer: An instant-read thermometer is great for quick temperature checks, while a leave-in probe lets you monitor the steak as it cooks and makes it easier to pull it at the right temperature.

How to Pan-Sear a Flat Iron Steak

Optional: Trim and Portion the Flat Iron

Skip this step if your steak is already trimmed and portioned.

If you bought a whole flat iron, pat it dry well with paper towels. Use a sharp knife to trim off any excess fat from the outside, then cut it into 2 or 3 smaller steaks. Ideally, each steak should be about 1 inch (2.5 cm) thick and weigh around 12 oz (340 g), so it fits comfortably in the skillet and cooks evenly.

Dry-Brine the Flat Iron Steak

If you haven’t already, pat the steak dry on all sides with paper towels. Season it on both sides with salt equal to about 1% of the steak’s weight. That’s enough to season the meat well without making it overly salty.

For a 12 oz (340 g) flat iron steak, that’s about 0.12 oz (3.4 g) of salt, or roughly:

• 1 1/4 teaspoons Diamond Crystal kosher salt,
• 3/4 teaspoon Morton kosher salt,
• 1/2 teaspoon table salt.

Place the salted steak on a wire rack set over a baking sheet and refrigerate it uncovered for at least 1 hour. For best results, refrigerate it for 3 to 4 hours; I usually go closer to 4.

If you don’t have at least an hour, don’t salt the steak ahead of time. Season it immediately before searing instead, or add salt to the sliced steak after cooking.

Make the Garlic-Herb Compound Butter

While the steak is dry-brining, make the garlic-herb butter. Cut the butter into small cubes, place them in a small bowl, and let them soften at room temperature until you can easily mash them with a fork. If you’re short on time, microwave the butter in 5-second bursts, checking after each one so it doesn’t melt completely.

Add the garlic, pepper, salt, parsley, and rosemary, then mash with a fork until combined. Taste and adjust the seasoning if needed, then cover and refrigerate until ready to use.

Preheat the Pan

About 15 minutes before you’re ready to cook, take the flat iron steak out of the refrigerator. Take the compound butter out at the same time so it can soften before serving.

Searing steak creates a lot of smoke, so turn on the exhaust fan or open a window before heating the pan. Heat a heavy skillet over medium-high heat for 3 to 4 minutes. Add 2 tablespoons of high-smoke-point oil and heat for another minute.

After about 4 to 5 minutes, the oil should be shimmering and just starting to smoke. At that point, the pan is ready for searing.

Pan-Sear the Flat Iron Steak

Pat the flat iron steak very dry with paper towels, then carefully place it in the hot skillet. Press it down lightly with tongs so the steak makes full contact with the pan. Sear the steak, flipping every 30 seconds, to build a deep, even crust.

After about 3 minutes, start checking the internal temperature. Insert the meat thermometer horizontally into the thickest part of the steak. Once it reaches the pull temperature listed in the chart below, transfer it to a cutting board or plate, top with 1-2 tablespoons of compound butter, and let it rest for 5 minutes.

Pan-Seared Flat Iron Steak Temperature Chart

Desired doneness	Pull at internal temp	Final temp after resting
Rare	110°F (43°C)	125°F (52°C)
Medium-Rare	120°F (49°C)	135°F (57°C)
Medium	130°F (54°C)	145°F (63°C)
Medium-Well	140°F (60°C)	155°F (68°C)
Well-Done	150°F (66°C)	165°F (74°C)

Slice and Serve

After resting, slice the flat iron steak against the grain. Cutting across the muscle fibers shortens them, making each bite easier to chew. Slice with the grain and even a perfectly cooked steak will feel noticeably tougher.

Serve with your favorite sides.

What Is the Best Doneness for Pan-Seared Flat Iron Steak?

In my opinion, medium-rare to medium, around 135 to 145°F (57 to 63°C), is the sweet spot for pan-seared flat iron steak. Flat iron is naturally well marbled, and cooking it to this range gives the intramuscular fat (marbling) enough heat to soften and render. As the fat renders, it loses its firm, waxy texture and gives the steak a richer beefy flavor, a more buttery mouthfeel, and a juicier, more tender bite.

Don’t cook flat iron steak too rare. Below about 130°F (54°C), the intramuscular fat stays firm and waxy, so the steak has a texture that I don’t like and most people won’t either. On the other hand, once you go past medium, it starts losing much of its tenderness and juiciness, but the generous marbling keeps it rich and flavorful even when cooked further.

What to Serve with Pan-Seared Flat Iron Steak

A good, well-marbled flat iron steak doesn’t need much on the side. I like to keep the sides simple so the steak stays the main focus. These are the ones I serve most often:

• Crispy Roasted Potatoes
• French Fries
• Mashed Potatoes
• Steakhouse Potato Wedges
• Arugula Salad
• Tomato and Red Onion Salad
• Roasted Broccolini
• Roasted Asparagus

Tips for the Best Pan-Seared Flat Iron Steak – Key Takeaways

• Choose a thicker steak: For best results, choose a flat iron steak about 1 inch (2.5 cm) thick or thicker.
• Look for more marbling: A well-marbled steak will be more tender, juicy, and flavorful.
• Cut a whole flat iron muscle into smaller pieces: If you have a whole flat iron, cut it into a few smaller pieces of similar thickness so they cook evenly.
• Dry the steak well: Pat it thoroughly with paper towels before salting, then dry it again right before searing. A dry surface develops a better crust.
• Dry-brine for 3 to 4 hours: A few hours of dry brining gives the salt time to season the meat more deeply. Another benefit is that most of the surface moisture has time to evaporate while the steak rests in the refrigerator. With less moisture to evaporate when the steak hits the pan, more of the heat goes straight into browning, resulting in a deeper, more even crust.
• Use about 1% salt by weight: 1% is a safe amount that guarantees a deeper flavor without the risk of over-salting the steak.
• Don’t salt it 2 to 45 minutes before cooking: Salting it about 2 to 45 minutes in advance draws moisture to the surface, making it harder to get a deep, well-browned crust, especially with thinner cuts.
• Use a heavy skillet: A cast-iron skillet is the best choice for this recipe, but carbon steel and heavy-bottomed stainless steel are both good alternatives.
• Preheat the pan well: Heat the skillet over medium-high heat for 3 to 4 minutes. Add the oil and heat it for another minute before adding the steak.
• Use a high-smoke-point oil: Choose an oil with a smoke point of at least 450°F (232°C).
• Use a meat thermometer: Don’t rely on cooking time to judge doneness. Steak thickness, starting temperature, and pan heat all affect how quickly it cooks.
• Flip the steak every 30 seconds: Flipping often helps it cook more evenly and gives you better control over the crust.
• Pull it before it hits your target temp: Don’t wait until the steak is only 5°F (3°C) below your target temperature. After a hard sear, the temperature will rise quite a bit as it rests. I pull a flat iron steak about 15°F (8°C) below my target, then let it rest for 5 minutes.
• Rest it with butter: Top the steak with compound butter while it rests. The butter will melt over the hot steak, adding richness and plenty of garlic-herb flavor.
• Cook it medium-rare to medium: Flat iron steak stays juicy, tender, and full of beefy flavor at this doneness.
• Slice it against the grain: Cut the steak into thin slices across the grain. This shortens the muscle fibers, making each bite easier to chew.

I cover these tips in more detail in my guide to cooking steak on the stove.

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Try Some of My Other Steak Recipes

• Pan-Seared Ribeye Steak
• Pan-Seared Top Blade Steak
• Pan-Seared Hanger Steak
• Pan-Seared Filet Mignon
• Pan-Seared Strip Steak