A flat iron steak is a highly marbled, tender, and flavorful cut of beef from the cow’s shoulder (chuck). Known for having the tenderness of a filet mignon but the robust flavor of a ribeye, it gets its name from its distinctive, flat, rectangular shape.

Why Flat Iron is So Popular

The flat iron (scientifically the infraspinatus muscle) is widely considered by butchers to be the second most tender cut on the animal, right after the tenderloin. Because this muscle doesn’t get a heavy workout, the meat is naturally soft. It is also highly prized because it offers premium steakhouse quality and rich marbling at a significantly lower price point than center-plate cuts.

How to Cook It

Because of its uniform thickness, the flat iron is perfect for high-heat cooking.

• Cooking method: It excels on the grill, in a cast-iron skillet, or broiled.
• Target doneness: The consensus among chefs is to cook it to medium-rare (around 135°F or 57°C) to prevent it from drying out.
• Slicing: Always slice the flat iron thinly against the grain to maximize its tenderness.