Jun 14, 2018

Cast Iron Flank Steak

Marinated in the best flank steak marinade ever (imho), my recipe for Cast Iron Flank Steak, is delicious, LOW CARB, quick & easy to make, and one of my FAVORITE go-to easy dinner ideas!
Marinated in the best flank steak marinade ever, my recipe for Cast Iron Flank Steak, is delicious, LOW CARB, quick & easy to make, and one of my FAVORITE go-to easy dinner ideas! #LTGrecipes

Flank Steak

Flank steak is a quick and easy dinner any night of the week. It is very lean with an intense beefy flavor, high in protein, and low carb too. Perfect for a low carb, keto lifestyle. Flank steak is also a budget friendly cut of beef, and the leftovers are easy to use in other recipes such as flank steak fajitas or stir fry making flank steak a smart choice when meal planning.

Tips for cooking the perfect flank steak every time:

  • Use Certified Angus Beef ® brand for maximum flavor and tenderness
  • Marinate the flank steak for at least 30 minutes prior to cooking.
  • Cook flank steak to mid-rare. Please don't overcook flank steak! If you need your beef cooked more, I'm sorry to break it to you, flank steak might not be for you. Flank steak is very lean, as a result, it is not as tender of a cut. Even if you are used to cooking your beef more, I encourage you to give flank steak a try at mid-rare. It's a real treat!
  • Slice flank steak thinly and against the grain for maximum tenderness. It's very easy to see the grain on flank steak, so it's easy to tell which way to cut. Cutting against the grain shortens the fibers making steak as tender as it can be. Always cut against the grain for best results.
  • Use a seasoned cast iron skillet for best results
Marinated in the best flank steak marinade ever, my recipe for Cast Iron Flank Steak, is delicious, LOW CARB, quick & easy to make, and one of my FAVORITE go-to easy dinner ideas! #LTGrecipes

Cast Iron Flank Steak

I prefer to cook flank steak in a screaming hot cast iron skillet to get the best sear on the outside of the steak. The chemical reaction that takes place when you sear a steak (Maillard Reaction) creates flavor compounds, so that sear is definitely necessary when cooking steaks as it adds loads of flavor!

Cooking a Cast Iron Flank Steak is the best way to get that sear, in my humble opinion, as more of the surface area of the flank steak will be seared as opposed to cooking on a grill. Bonus, because it's indoor cooking, you can cook a cast iron flank steak year round! I feel the same about Cast Iron Chicken Breasts. Cast iron gets the best sear!

There are benefits, however, to grilling a flank steak. If you want that smoky flavor you can only get from the grill, then go for it! Grilled flank steak is delicious too.
Marinated in the best flank steak marinade ever, my recipe for Cast Iron Flank Steak, is delicious, LOW CARB, quick & easy to make, and one of my FAVORITE go-to easy dinner ideas! #LTGrecipes

Best Flank Steak Marinade Ever

I realize saying this is the best flank steak marinade ever is a strong statement, but this is my favorite marinade for flank steak, so that makes it the best (imho). Don't let the long-ish ingredient list scare you when making this flank steak marinade.

Although there are several ingredients, it really only takes a few minutes to whisk the ingredients together. It's totally worth it as the flavor really does come through and compliments the flank steak nicely.

The acid in the marinade helps to tenderize the flank steak, and the oil in the marinade means you don't have to oil the cast iron skillet when cooking the flank steak. This marinade is especially good if you plan to use leftovers to make flank steak fajitas.

How to Make Cast Iron Flank Steak

This is a very simple recipe taking just 10 minutes to cook. I try to get the marinade whisked together early in the day, so the flank steak can marinate for about 6 hours. However, I have marinated as little as 30 minutes and the flavor of the marinade still comes through.
Whisking up the flank steak marinade to make cast iron flank steak
I marinate in a gallon sized, zip-top bag as pictured below. Using a zip-top bag makes it easy to coat the flank steak in the marinade, however, any container that fits the flank steak with the marinade is fine. Keep in mind you want to submerge the flank steak in the marinade or turn it over halfway through marinating if needed.
Flank steak marinating in the flank steak marinade in a zip top bag until ready to make cast iron flank steak
To cook the cast iron flank steak, preheat a cast iron skillet over mid-high heat. Remove the flank steak from the marinade and discard the marinade. Place the marinated flank steak into the cast iron skillet and let it sear for 5 minutes or until the flank steak develops a nice crust on the one side. Using tongs, flip the flank steak over and sear the other side for 5 minutes or until cooked to medium rare. If your skillet gets a little dry when cooking the flank steak, add a tablespoon of butter as needed. Test the temperature of the flank steak using an instant-read thermometer inserted into the thickest part of the meat. The temperature of the flank steak should be 120-125°F to allow for cook over when resting the steak.
Cast Iron Flank Steak searing in a cast iron skillet on both sides
Remove the flank steak from the cast iron skillet to a rack for resting. I place the rack on top of a foil lined baking sheet to minimize mess. Resting on a rack keeps the flank steak out of any drippings that accumulate which helps to maintain the beautiful crust. Allowing steak to rest in its juices can soften the crust which affects the texture of the steak. Rest the flank steak for 5-10 minutes before slicing.
Cast iron flank steak resting on a rack before slicing
Slice the flank steak thinly across the grain for maximum tenderness. See the photo below for reference. You can clearly see the grain of the flank steak, so it's fairly easy to determine how to slice.
Slice cast iron flank steak thinly across the grain for maximum tenderness

What to Serve with Cast Iron Flank Steak

For a low carb meal, I like to serve Cast Iron Flank Steak with a garden salad. If I'm feeling generous I'll microwave a baked potato for the hubs to go along with his flank steak and salad. He loves his carbs! Here are more serving suggestions that I feel pair nicely with flank steak:

Cooking Tools Recommended to Make Cast Iron Flank Steak

Most home cooks will already have the tools you need to make this recipe as you just need some basics. Here is a list of tools I use when making Cast Iron Flank Steak. Disclosure: Life Tastes Good is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program. Please note: The following links are affiliate links to products I use and love.
Cast Iron Flank Steak on Pinterest

How to cook flank steak
Yield: 6 Servings

Cast Iron Flank Steak

Marinated in the best flank steak marinade ever (imho), my recipe for Cast Iron Flank Steak, is delicious, LOW CARB, quick & easy to make, and one of my FAVORITE go-to easy dinner ideas!
prep time: 10 minscook time: 10 minstotal time: 20 mins


Flank Steak Marinade
  • 1/2 cup olive oil
  • 3 tablespoons Worcestershire sauce
  • 1/4 cup fresh lime juice (about 2 limes, juiced)
  • 1 tablespoon garlic, minced
  • 1 teaspoon ground cumin
  • 1/2 tablespoon chili powder
  • 1/2 teaspoon red pepper flakes
  • 1 tablespoon sugar
  • 1 teaspoon kosher salt
  • 1/2 teaspoon freshly cracked black pepper
  • 2 lbs Flank Steak


Flank Steak Marinade
  1. Combine 1/2 cup olive oil, 3 tbsp Worcestershire sauce, 1/4 cup fresh lime juice, 1 tbsp minced garlic, 1 tsp cumin, 1/2 tbsp chili powder, 1/2 tsp red pepper flakes, 1 tbsp sugar, 1 tsp salt, & 1/2 tsp pepper and whisk to combine.
  2. Place flank steak into a gallon sized zip-top bag and pour flank steak marinade into bag. Zip to close tightly. Place bag in refrigerator for at least 30 minutes and up to 8 hours.
Cast Iron Flank Steak
  1. Heat a 12-15" cast iron skillet over mid high heat. Remove flank steak from marinade. Discard marinade.
  2. Place flank steak in hot skillet and sear for about 5 minutes or until a nice crust forms on the one side of the flank steak.
  3. Using tongs, turn flank steak over and sear the other side for about 5 minutes or until cooked to 120°F.
  4. Remove flank steak from skillet and rest 5-10 minutes. Slice thinly across the grain. Serve and enjoy!


*Total time does not include marinate time
*Cook times may vary due to thickness of your flank steak. Always use an instant-read thermometer to determine meat is done.
fat (grams)
sat. fat (grams)
carbs (grams)
protein (grams)
sugar (grams)
Created using The Recipes Generator
Nutrition label disclaimer: Nutrient values are estimates only. Variations may occur due to product availability and food preparation. To obtain the most accurate representation of the nutritional information in a given recipe, you should calculate the nutritional information with the actual ingredients used in your recipe, using your preferred nutrition calculator. You are solely responsible for ensuring that any nutritional information provided is accurate, complete, and useful.


  1. Yeah bookmaking this wasn't a bad decision outstanding post!

  2. Love the recipe! it is easy to make and the instructions were right on the dot to get the perfect crust

    1. So glad you enjoyed it! That crust is everything, right?!!

  3. My mom and I made this for dinner tonight, and while we really enjoyed the flavour of the marinade, it didn’t cook as expected based on the instructions. It was smoking A LOT in the cast iron pan and the outside ended up burnt. I would probably turn the heat down next time, and use an oil with a higher smoke point.

    1. Hi Sarah, I do recommend cooking on medium high heat, however, if you find that is too hot on your stovetop and the steak if cooking too quickly, then definitely adjust it as needed. You do want to get a good sear on the steak for maximum flavor, but there is a fine line and it can burn if you're not careful, so definitely turn down the heat when needed. Thanks for giving it a try! ~Marion

  4. Would it work well to use lemon instead of lime juice and would omitting the sugar make a big difference?

    1. Lemons & lime do have a significant taste difference, so yes, it would affect the overall taste of the dish. Because flank steak cooks so quickly, the sugar helps to get a good sear on the outside for more flavor, but you can certainly omit it if you prefer. I hope that helps! ~Marion

  5. Hello! Do you not recommend to marinate overnight? It says from 30 mins to 8 hours so overnight is definitely longer than 8 which is Max. Thoughts? Thanks!

    1. Hi Jackie, Great question! I don't recommend marinating overnight as it breaks down the meat to the point where it can alter the texture and make it weird. I hope that helps! Stay safe and have a wonderful week ~Marion

    2. It sure does! Thanks so much trying it tonight!! :)

  6. How long do you pre-heat the cast iron skillet over medium heat?

    1. You'll want to preheat 3-5 minutes. Usually when the handle starts to get hot you know the pan is ready. Remember to protect your hands from the cast iron skillet handle as it will continue to get hotter as you cook.

  7. Just finished dinner, this flank steak was great!! I am more of a medium well guy so I let the steak for about 7-8 minutes each side. The result was great. Health freak so I skipped the sugar for the marinade but it was still great taste, with a glass of Chianti of course :))). Thank you, this recipe is a keeper!!

  8. I’m not a big steak eater, but I absolutely loved this dish! I served it with sautéed brussels sprouts and a salad for a healthy meal. I am adding this recipe to our regular meal rotation. FYI - your cast iron chicken breasts recipe is a go-to of mine as well!

    1. Thank you so much for your kind words, Andi! I'm so happy you enjoy the recipes. It really makes my day to hear this. Thanks again! Have a tasty week!! ~Marion


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