The Absolute Best Marinated Flat Iron Steak
Flat iron steak might just be the most underrated cut at the butcher counter. It’s tender, deeply flavorful, affordable and perfect for grilling season. The key is a great marinade. This marinated flat iron steak is sweet, smoky, tangy, and garlicky. The marinade creates a gorgeous crust on the steak and infuses it with impossibly good flavor. With just a few pantry staples and some time to marinate, you’ll have a juicy steak that tastes like it came from a steakhouse, but made right in your backyard.
Erica’s Thoughts
There was a time in my life when I thought a good, flavorful steak required a thick ribeye or filet mignon, a meat thermometer, and some intimidating reverse searing technique. Then I discovered the beauty of a flat iron steak. Like many of my meals, this flat iron steak recipe is inspired by my mother-in-law. She made it for us when we visited Arizona this year and I knew immediately that I’d need to recreate it for the blog. I’m generally not a big red meat gal but dangggg, I could not get enough. She sliced it super thinly and I kept coming back for piece after piece.
The marinade is the perfect balance of umami, salty, tangy and sweet. The brown sugar creates this caramelized crust when it’s grilled that is just so, so irresistible. I love to serve it roasted potatoes, grilled vegetables and a big green salad. One great thing about this recipe is that you can prep it up to a day ahead of time, and then when you’re ready to eat, throw the marinated steak on the grill and dinner is served!
What is flat iron steak?
A flat iron steak is a beautifully marbled, tender, and flavorful cut of beef that comes from the shoulder area of the cow, specifically the top blade roast. It was once overlooked because of a tough connective tissue running through it, but butchers figured out how to remove that seam, and voilà, the flat iron steak was born. There is still a connective vein throughout the steak but you can trim some of it away and/or give it a few whacks with a meat mallet to tenderize it.
3, 2, 1 – it’s time to make a restaurant-worthy steak in your backyard all summer long.
What You’ll Need to Make Marinated Flat Iron Steak
Flat iron steak: flat-iron steak is a well-marbled, tender cut that cooks quickly and soaks up marinade like a champ. I always get this from my local grocery store (Fred Meyer) and if i don’t see it displayed I ask the butcher and they can usually get one for me!
Olive oil: olive oil helps carry flavor into the steak and keeps things juicy on the grill. You could also use vegetable oil.
Low-sodium soy sauce: soy sauce adds savory umami and balances the sweetness.
Red wine vinegar: the acidity in vinegar provides brightness and helps tenderize the meat. Most vinegar types will work- if you don’t have red wine vinegar, try balsamic vinegar or apple cider vinegar.
Worcestershire sauce: Worcestershire brings that deep, meaty flavor- def don’t skip this!
Brown sugar: brown sugar is key for balancing the other flavors in the marinade and encouraging caramelization on the outside of the steak.
Garlic: fresh garlic is the best way! You could also use garlic paste or garlic powder in a pinch.
Red pepper flakes: pepper flakes offer a subtle kick that doesn’t overpower.
Steak seasoning: another key ingredient, so get one you really like! I like the very simple mixes that have kosher salt, black pepper and garlic like this Kinders The Blend seasoning.
Smoked paprika: adds a subtle smoky depth of flavor.
How to Make This Flat Iron Steak Marinade Recipe
Pat the steak dry and trim any large pieces of fat. Use a meat mallet to the steak a few times to tenderize.
Place the steak in a large resealable bag or shallow dish. In a jar or mixing bowl, whisk together marinade ingredients.
Pour that delicious marinade over the steak, seal the bag, and smoosh everything around to coat evenly. Refrigerate for at least 4 hours, up to 24 hours. Flip and squish around the bag a few times throughout the marinating process.
Remove steak from the fridge 30-60 minutes before cooking to come to room temp. Preheat a grill or grill pan over high heat. Oil the grill grates by using a brush or a paper towel with a little oil. Let excess marinade drip off the steak.
Place steak on the preheated grill and cook for about 5 minutes per side, or until internal temperature reaches 140–145 degrees F (for medium rare to medium steak). Whip up any side dishes while the steak cooks.
Let steak rest on a cutting board, tented with foil, for 10 minutes. Slice thinly across the grain and drizzle with any juices. Serve with potatoes, a huge green salad and grilled veggies!
Expert Tips
- Don’t skip the rest time, it helps the juices redistribute.
- Flat iron steak is best served medium-rare to medium. Overcooking can dry it out.
- You can make the marinade ahead and freeze the steak in the marinade. Just defrost overnight in the fridge.
- Always slice flat iron steak thinly against the grain for the most tender bite.
- This tender steak is delicious as is but loooove steak served with chimichurri!
- Garnish the serving platter with fresh rosemary, green onions or thyme to make it look extra pretty.
FAQs
Anywhere from 4 hours to 24 hours. Longer = more flavor, but don’t go beyond 24 hours or the texture can get weird.
You can make this on an indoor grill cast iron pan or a large cast iron skillet. If you have an indoor grill pan, grill on high for 5 minutes per side, same as an outdoor grill. To bake, preheat your oven to 400°F. Heat a large cast iron skillet over high heat and sear the steak for 2 minutes per side. Transfer to the oven and cook for 10 minutes for medium rare and 12-13 minutes for medium.
For medium-rare, aim for 130-135°F. Medium is around 140-145°F. Use an instant-read thermometer for best results.
Cuts that are similar to flat-iron are flank steak, skirt steak and hanger steak. The cooking time will vary slightly depending the cut of meat you use.
Mashed potatoes, roasted potatoes, balsamic asparagus, spring pea salad (pictured), garlic bread or a simple pasta dish. Dipping sauces I love: chimichurri sauce, roasted garlic aioli or a good ole steak sauce.
Store leftovers in an airtight container in the fridge for up to 5 days. You can use it to make steak quesadillas, steak salad, steak and eggs, steak fried rice, steak sandwiches or wraps or steak nachos!
If you love this marinated flat iron steak you’ll love this other dinner inspo:
Arugula and steak salad with lemon dressing
If you try and like this recipe please don’t forget to leave a comment and star rating down below! If you love more lifestyle, behind the scenes and ‘eating in real life’ type of content come find me over on Instagram, @itsaflavorfullife, I love connecting with you all there!
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The Absolute Best Marinated Flat Iron Steak Recipe
- Prep Time: 15 minutes
- Cook Time: 10 minutes
- Total Time: 25 minutes + 4 hours to marinate
- Yield: 6 servings 1x
- Category: Beef
- Method: Grill
- Cuisine: American
Description
Juicy, flavorful, and easy to make, this marinated flat iron steak features a sweet, smoky, garlicky marinade that grills up perfectly tender every time.
Ingredients
- 2lb flat iron steak
- 3 tablespoons olive oil
- 2 tablespoons low-sodium soy sauce
- 3 tablespoons red wine vinegar
- 1 tablespoon Worcestershire sauce
- 1/4 cup brown sugar
- 3 large cloves garlic, minced
- 1/2 teaspoon red pepper flakes
- 2 teaspoons steak seasoning (I use this Kinders blend and it’s awesome!)
- 1 teaspoon smoked paprika
Instructions
- Pat steak dry with a paper towel. Use a pair of kitchen scissors to trim away any large, visible pieces of fat. Optional but recommended, use a meat mallet and smack the steak a few times to tenderize it. It doesn’t need much but pounding helps break down tough muscle fibers, making the final bite softer and easier to chew. Place the steak in a gallon-sized Ziplock bag or a shallow baking dish.
- Shake or whisk together 3 tablespoons olive oil, 2 tablespoons soy sauce, 3 tablespoons red wine vinegar, 1 tablespoon Worcestershire sauce, ¼ cup brown sugar, 3 large cloves of minced garlic, ½ teaspoon red pepper flakes, 2 teaspoons steak seasoning and 1 teaspoon smoked paprika until well combined. Pour the marinade over the steak and seal the Ziplock bag. Smoosh everything around so you really coat the steak in marinade.
- Marinate in the fridge for 4 hours, up to 24 hours. If you remember, try to flip or rotate the bag once or twice throughout the marinating process.
- Take the steak out of the fridge and let sit at room temperature for 30-60 minutes before cooking. Preheat your outdoor grill or indoor cast-iron grill pan to high. Use a brush or an oiled paper towel to oil the grill grates. Remove the steak from the marinade, letting the excess drip off, and place it on a hot grill. Close grill and cook for 5 minutes. Flip the steak and grill for another 5 minutes. Grilling for exactly 10 minutes should yield a medium-rare steak (see note for additional cooking times).
- Place steak on a large cutting board and let rest for 10 minutes. Use a serrated knife to cut thin slices cross-wise on the bias. Drizzle any juices over the sliced steak. Serve with roasted or mashed potatoes, grilled vegetables, green salad and/or garlic bread!
Notes
Cook time: For a ~1-inch thick flat iron steak grilled on high heat cook 3-4 minutes per side for rare, 4-5 minutes per side for medium rare, 5-6 minutes for medium well. I wouldn’t recommend cooking much longer than this because flat iron steak can dry out pretty quickly.
Oven Instructions: Preheat the oven to 400°F. Heat a large cast iron skillet (or other oven-safe skillet) over high heat. Add a touch of high-heat cooking oil. When the oil is hot, remove the steak from the marinade, letting the excess drip off, and place in the hot pan. Sear the steak for 2 minutes per side and then transfer to the preheated oven for 10-12 minutes. Using a meat thermometer is the best way to prevent overcooking, since all ovens are a little different. Aim for 135°F for medium rare and 140-145°F for medium.
Refer to the above blog post for step-by-step photos, expert tips and answers to frequently asked questions.
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Nutrition
- Serving Size: 4oz cooked steak
- Calories: 260
- Sugar: 6.5 g
- Sodium: 448.8 mg
- Fat: 10 g
- Carbohydrates: 7.7 g
- Fiber: 0.2 g
- Protein: 32.9 g
- Cholesterol: 90.7 mg
My husband absolutely loved this! It was so delicious. We used the leftover steak for steak and rice bowls. Will definitely make again
Yessss, happy to hear Jennifer! One of my husband’s favorites as well. Thank you for making this and for your review!
Oh my. This IS the absolute best steak! I have never had a flat iron steak before and Erica is 100% right. It’s so tender. The marinade is delicious and overall the recipe is really easy. I used a grilled pan and it turned out perfectly.
Yaaaaay! I am so happy you loved it Julie! Thanks for trying it and thanks for your review! 😍🥩
A couple Sundays ago, I invited my parents over for dinner – and then realized I had no idea what to make and very little time to cook because my husband and I were working on house projects. Luckily, I had just seen Erica post about this recipe and it looked easy, so we decided to give it a go – it was great! The steak was so easy to make, it was delicious, and since it’s grilled, there were basically no dishes to clean up – win, win, win! Like Erica said, I had to ask the butcher at my grocery store to cut me a piece of flat iron, but they were happy to do it and I was pleasantly surprised by the price! We will definitely be making this again, especially now that summer grilling season is here! Thanks for the great recipe!
Yaaaay! This made my day Amanda, thank you!
This marinade made our steak so flavorful!!!! Gah!!! It was super easy to throw together. I marinated the meat during the day- so on a random Tuesday we were eating like kings with this amazing, tender, juicy steak.
So so good! I marinated it in a ziploc bag and then put it in the freezer until we were ready to grill it 2 days later. I served it with roasted veggies and rice made with beef broth. Everyone in my family gobbled it up! Thanks Erica!
This recipe looks great but i have 4 6oz flat iron steaks. Not sure if I can change the recipe for that?
Hi Jenni, are you sure they are flat iron? Generally flat iron doesn’t come quite that small. Either way, you can still totally make the recipe! The marinade doesn’t need any changes but the cook time may vary slightly based on your smaller steaks. If they are indeed flat iron, I’d recommend starting with 4-5 minutes per side on high (assuming you’re using a grill). They’ll look quite charred on the outside but should be perfectly medium rare when you thinly slice. When in doubt, use a meat thermometer, you’re going for 130-135 F for medium rare.
We made 2 flank steaks…one with this marinade and one with another marinade recipe and this one was the overwhelming favorite!
Woot woot! Love to hear it, thank you!
Made this Saturday and it was so delicious. My guests asked for the recipe 🙂
Yaaay! Happy to hear it Brigitte! I’m sure your guests were so pleased to be blessed with good steak! 😉
Ohhh this steak was delicious on our pellet grill! We marinated for 24 hours and chose a top sirloin due to availability and it did not disappoint. The flavors were phenomenal—the red wine vinegar was a hit.
Used skirt steak and a grill pan, amazing!
This was amazing and I followed the recipe to the letter! I highly recommend!!!
Woohoo! Happy to hear it Joanie, thanks for trying it!