A four-hour marinating process and a quick trip to the grill make this grilled flat iron steak recipe a keeper.

Grilled Flat Iron Steak

So, you may be wondering what is flat iron steak, anyway? Flat iron steak is a versatile and decidedly budget-friendly cut of beef that’s good for grilling, broiling or pan-searing. The flat iron steak is also known as top blade steak and shoulder top blade steak, as it comes from beside the cow’s front shoulder.
The fact is that flat iron steak, which is named for its resemblance to an old fashioned flat iron, can be delicious when it’s marinated and cooked properly, and that’s what we’re going to do here today.
Grilled Flat Iron Steak Ingredients
- Fresh lime juice: A healthy dose of lime juice serves as the basis of the marinade that infuses the steak with flavor. The long marinating process also helps make this tougher cut of meat more tender.
- Olive oil: It’s no surprise to find olive oil in a steak marinade recipe. If you don’t have olive oil on hand, you can use a different oil, like avocado.
- Garlic cloves: Make sure the garlic cloves are very well minced so their flavor fully infuses into the meat. You can also use store-bought frozen garlic cubes. Thaw them and mix the garlic in well.
- Chili powder: A welcome spice that brings some heat, this is also one of the spices you can leave out of this recipe if you have a very low tolerance for spicy foods.
- Ground cumin: Cumin has a wonderful but powerful flavor, so don’t use too much of it—measure the ground cumin with care before adding it to the marinade.
- Kosher salt: We don’t usually bother mentioning salt specifically, but in this case, you’ll be using a lot of it, and it’s best to use kosher salt, so we’re calling it out.
- Pepper: So too with the pepper, we’re mentioning it this time. You should use one teaspoon coarsely ground pepper.
- Crushed red pepper flakes: Most people will love the bit of heat added by crushed red pepper flakes, but this is the other ingredient to skip if you want to reduce the spiciness of this steak.
- Beef flat iron steak: You can’t enjoy a fine flat iron steak if you don’t have any. This recipe is designed for one and a half pounds of flat iron steak.
Directions
Step 1: Prepare the marinade
In a small bowl, whisk together the lime juice, olive oil, minced garlic, chili powder, cumin, salt, pepper and red pepper flakes, working until well-blended. Pour the marinade into a shallow dish, then add beef, turning it to coat both sides. Cover the dish and refrigerate it for up to four hours, flipping the meat halfway.
Step 2: Grill and rest
Drain the beef, discarding marinade. Then grill the steak, covered, over medium-high heat until the flat iron steak reaches your desired doneness (for medium-rare, a thermometer should read 135°F; medium, 140°; medium-well, 145°), usually for about five to six minutes on each side. Then let the steak stand five minutes.
Step 3: Cut across the grain
Cut the steak diagonally across the grain into thin slices, then serve.
Grilled Flat Iron Steak Variations
- Use top sirloin steak instead: This exact recipe will work perfectly well with a top sirloin steak. And of course the marinade is good with other cuts, too, but the approach to the grilling is spot-on for sirloin.
- Swap in lemon juice: If you don’t have lime juice or want an even tangier steak, use lemon juice in place of the lime juice in the marinade.
- Add some sugar: Adding a heaping teaspoon of brown sugar to the marinade adds a sweetness to the steak that will be great enjoyed in many dishes, like in fajitas.
How to Store Grilled Flat Iron Steak
This flat iron steak will keep well in an airtight container in the fridge for up to three days. To reheat it, pop it in an oven at 300º in a baking dish with a few tablespoons of broth. You can also warm it on the stove in a pan, again adding some broth.
Can you freeze cooked steak?
Some steaks take to freezing after they have been cooked, but this isn’t one of them—it would be far too tough and chewy to enjoy once thawed.
Grilled Flat Iron Steak Tips
Why do you cut flat iron steak across the grain?
You should cut flat iron steak across the grain to make it as tender as possible and less chewy. Flat iron steaks are tougher cuts of meat with long muscle fibers (or grains) that run in one direction. Cutting with the grain would leave those fibers intact, resulting in a tougher bite. Instead, cutting across the grain breaks down the fibers into shorter pieces, which makes the meat easier to chew and enjoy.
Do you need to tenderize flat iron steak?
Flat iron steak does not need to be tenderized prior to cooking, provided you allowed plenty of marinating time.
How should I serve grilled flat iron steak?
This steak is at its best when it’s sliced thin and served in tacos, burritos, fajitas or salads.
Grilled Flat Iron Steak with Chili, Garlic, and Lime
Ingredients
- 3 tablespoons fresh lime juice
- 1 tablespoon olive oil
- 4 garlic cloves, minced
- 1-1/2 teaspoons chili powder
- 1-1/2 teaspoons ground cumin
- 1-1/2 teaspoons kosher salt
- 1 teaspoon coarsely ground pepper
- 1 teaspoon crushed red pepper flakes
- 1-1/2 pounds beef flat iron steak or top sirloin steak
Directions
- In a small bowl, whisk the first 8 ingredients until blended. Pour into a shallow dish. Add beef; turn to coat. Cover and refrigerate for up to 4 hours.
- Drain beef, discarding marinade. Grill, covered, over medium-high heat until meat reaches desired doneness (for medium-rare, a thermometer should read 135°; medium, 140°; medium-well, 145°), 5-6 minutes on each side. Let steak stand 5 minutes.
- Cut diagonally across the grain into thin slices.