What is a Flat Iron Steak? The Underrated Chuck Cut That Rivals Ribeye

If you went to a butcher shop thirty years ago and asked for a Flat Iron Steak, you would have received a blank stare.

The Flat Iron simply didn't exist. It was buried inside the beef chuck (shoulder) as an un-butcherable piece of meat, destined to be ground into burger meat or slow-braised as a generic pot roast.

Today, the Flat Iron is one of the most highly sought-after cuts in the country, featured on high-end steakhouse menus and prized by backyard grillers for its incredible marbling, rich flavor, and melt-in-your-mouth tenderness.

At Milo Locker, we hand-carve premium Flat Iron Steaks as a star player in our Butcher's Cut 1/8th Bundle. Here is the incredible story of how modern meat science salvaged this underrated cut and how to prepare it to perfection.

The Science That Saved the Flat Iron

Like the Denver Cut, the Flat Iron is a product of modern culinary science.

In the early 2000s, researchers at the University of Nebraska and the University of Florida were tasked with finding value in the "chuck primal"—the heavy, tough shoulder muscle of the cow.

They focused on the infraspinatus muscle. They knew this muscle was exceptionally tender, but it had a massive, fatal flaw: a thick, tough band of connective tissue (collagen) ran directly through the center of the muscle, making it virtually impossible to grill or pan-sear.

Instead of cutting the muscle crosswise into tough steaks (which butchers historically called "top blade steaks"), the researchers developed a new butchery technique.

They figured out how to slice the muscle horizontally, completely removing the tough inner connective tissue band. This left two flat, uniform slabs of pristine, heavily marbled meat that resembled an old-fashioned flat iron.

When they tested the resulting cut, the results were shocking: the Flat Iron was determined to be the second most tender muscle on the entire animal, ranking just behind the tenderloin (filet mignon).

Why We Love the Flat Iron

The Flat Iron is a masterpiece of balance:

• Exceptional Tenderness: Because it ranks second in tenderness, it has a delicate, yielding texture that rivals a filet mignon.
• Deep Beef Flavor: Unlike the mild filet, the Flat Iron comes from the chuck primal, which is packed with rich, deep, beefy flavor and excellent marbling.
• Easy to Cook: It is uniform in thickness and flat, making it incredibly easy to sear evenly in a hot skillet or on a grill.

How to Cook a Flat Iron Steak

The Flat Iron is highly versatile and handles marinades beautifully, but because of its high quality and dry-aging, we recommend keeping it simple with salt, pepper, and high heat.

The Perfect Outdoor Grill Method

1. Bring to Temp: Take the Flat Iron out of the fridge 30 minutes before grilling. Pat it dry and coat lightly with olive oil or beef tallow.
2. Season: Season generously with coarse kosher salt, black pepper, and garlic powder.
3. Blazing Hot Heat: Set up your grill for direct, high-heat cooking (around 450°F–500°F).
4. Grill Fast: Place the Flat Iron directly over the hot coals or burners. Grill for 4 to 5 minutes per side. Because the Flat Iron is relatively flat, it cooks quickly.
5. Target Medium-Rare: Aim for an internal temperature of 130°F–135°F (medium-rare). Do not overcook this cut; going past medium will cause it to lose its signature tenderness.
6. Rest and Slice: Let the steak rest for 5–8 minutes. Crucial Step: Slice the steak thinly against the grain (perpendicular to the muscle fibers) at a slight angle.

Experience the tender, rich perfection of hand-carved, dry-aged Flat Iron steaks. Sourced from single-origin Iowa family farms and processed at Milo Locker. Take our quick quiz to find your recommended bundle.\n