Grilled Flat Iron Steak Recipe With Chimichurri Sauce

by Jim Casey
photo by Jim Casey

While a flat iron steak is a fantastic option for stir-fry, fajitas, and steak sandwiches, the cut is also flavorful—and tender—enough to stand on its own. A little EVOO, salt, pepper, and HIGH heat—and you’ve got yourself a dinner winner. Or, you can pair the flat iron steak with a number of bold-flavored sauces, including chimichurri, Béarnaise, or horseradish, among others.

It’s that simple with a flat iron steak, which comes from the shoulder (chuck) of the cow. The store-bought steak is typically a well-marbled, rectangular-ish cut that weighs between 1-2 pounds and ranges from 1/2-inch to 1-inch-thick. The key to this steak, in my meat-loving opinion, is grilling it at extremely high heat (600 degrees) very quickly. In fact, it will probably take you longer to make today’s accompanying chimichurri sauce than to grill this cut.

Let’s get grilling. Of course, if you’re looking for more great grilling recipes from Outsider, check out our Juicy Lucy Hamburgers, Blackened Salmon, Beer-Can Chicken, Pickle Juice Hot Wings, and more.

Ingredients: Flat Iron Steak & Chimichurri Sauce

Keep this flat iron steak recipe simple with just salt, pepper, and olive oil. Or feel free to pair it with a sauce, like homemade chimichurri.

Flat Iron Steak

  • 1.5-pound flat iron steak
  • 1 tbsp. extra virgin olive oil
  • 1 tbsp. coarse salt
  • 1 tbsp. coarse pepper

Liberally coat both sides of the steak with olive oil, salt, and pepper. Easy peasy. While the steak rests at room temperature, make the chimichurri sauce.

Liberally coat both sides of the steak with oil, salt, and pepper.

Chimichurri Sauce

  • 1 cup fresh parsley
  • 4 garlic cloves
  • 1 fresh jalapeno
  • 1/3 to 1/2-cup extra virgin olive oil
  • 2 tbsp. red wine vinegar
  • salt & pepper to taste

I like to keep my chimichurri sauce very simple, both in terms of ingredients and preparation. Various recipes call for the addition of oregano, red pepper, shallots, and more. And some recipes suggest hand-chopping and hand-mixing the ingredients. Feel free to do so, but I prefer to throw everything in a food processor and pulse a few times until it reaches the consistency of thick salsa. If you need to add a little more olive oil to get things spinning, go ahead. In addition, I like the heat, so I use the entire jalapeño (seeds and all).


Today, we’re using a Big Green Egg, but you can use any grill (charcoal or gas) for this recipe. Fill the Green Egg with lump charcoal and ignite. Wait for the Egg to get up to 600 degrees (usually takes about 20 minutes).

Get your grill up to 600 degrees, and cook the steak for about 3 minutes on each side.

Place the flat iron steak on the grill. Cook for about 3 minutes. Flip the steak, and cook an additional 3 minutes. For medium rare (which we suggest for this cut), remove the steak when it reaches an internal temperature of 125 degrees (about 6-7 minutes).

Let the steak rest for 5-10 minutes, until the temperature reaches 130 degrees. Slice, across the grain. Top with chimichurri sauce. Enjoy it with a cold Gratis beer.

Enjoy your flat iron steak masterpiece.