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Is flat iron steak good for sous vide? Yes! IMHO, sous vide is the best cooking method for flat iron steak. Learn to how to sous vide flat iron steak, including time and temp, the best flat iron marinade, and more. Cooking a flat iron steak to be tender not tough is easy, giving you a tasty source of inexpensive lean protein.

What is flat iron steak? Flat iron steak is a type of chuck steak, cut from the shoulder of the cow.
Another name for flat iron steak is oyster blade steak in Australia, or butler’s steak or feather blade steak in the UK. In the US, other names for flat iron steak include top blade steak and chuck steak.
Why is flat iron steak so cheap? Flat iron steaks come from the same part of the animal that you’d get a chuck roast. As a result, it tends to be an inexpensive cut of meat compared to a New York strip steak or ribeye.
Due to its delicious flavor and low price point, I’d say flat iron is better than strip steak. Unfortunately, it is not a popular beef cut and can be hard to find.
Flat iron steak has tough connective tissue running through it that’s typically removed by the butcher. Skillful butchering turns this previously unusable cut into something flavorful and tender (when cooked properly, of course).
Today you’ll learn how to make the most of your meat purchase with this beef chuck flat iron steak recipe. Let’s get to it!
➕ Flat Iron Steak Sous Vide Temperature
What temp is best for flat iron steak? Sous vide flat iron steak at 130 degrees Fahrenheit (54C) to cook it medium-rare. If you prefer steak more well done, you may want to use a higher temperature.
IMO, sous vide is the best method to cook beef flat iron steak to a perfect medium rare. With sous vide, you cook the steak in a vacuum-sealed bag in a temperature-controlled water bath. You can also use a Ziplock freezer bag with the air pressed out if you don’t have a vacuum sealer.
And if you don’t have a sous vide machine for the water bath, no worries. Some Ninja Foodi and Instant Pot machines can sous vide too!
🥩 How to Sous Vide Flat Iron Steak
Here are the step by step instructions for sous vide flat iron steak:
- Start with a piece of steak that is 1½ lbs. (680 grams) and ½-inch thick (1.27 cm). A larger or thicker steak may impact the cook time. Pat dry with a paper towel.
- Marinate the steak in Italian dressing for 6-8 hours in the refrigerator. Put the steak and marinade in a food-safe Ziplock bag to marinate, and flip the bag every few hours.
- Remove the steak from the marinade, and season both sides with steak seasoning.
- Put water in your sous vide machine (I use 18 cups in my Ninja Foodi). Heat the water bath to 130F (54C).
- Place the seasoned flat iron steak in a gallon-size freezer baggie with a zip top. Alternatively, seal the food in a vacuum sealed bag using a vacuum sealer.
- To sous vide using a freezer bag, you need to make sure the air is pressed out. Put the food in the bag, and partially seal it while pressing out as much air as possible. Next, partially submerge the bag in the hot water, making sure the food is under the water level.
- When you partially submerge the baggie, the rest of the air should move out. Then you can finish sealing the bag and completely submerge it in the water. Be careful not to burn your fingers!
- If using the Ninja Foodi, put the lid on with the vent open to sous vide. Sous vide flat iron steak for 2 hours at 130F (54C).
Flat Iron Steak Sous Vide Grill
How long do I grill a flat iron steak? After using the sous vide, sear or grill flat iron steak in 1 tablespoon of butter or olive oil for 1-2 minutes per side. Use a preheated skillet or grill pan that is heated to medium-high heat on the stove.
Let the steak rest for 10 minutes before slicing and serving. Cut flat iron steak against the grain into thin slices.
How to Cut Flat Iron Steak Against the Grain
To cut steak against the grain, first take a look at which way the lines (or streaks) run across the meat. Cut through these fibers, shortening them, instead of cutting alongside them. Cutting flat iron steak against the grain makes it easier to chew.
⭐ Flat Iron Steak Marinade
Does flat iron steak need to be marinated? How do you tenderize a flat iron steak? You technically don’t need to marinate flat iron steak. However, using a marinade is my secret to how to make flat iron steak tender.
I’m using a prepared light Italian dressing as a marinade to make life easier. You’re welcome to use your favorite steak marinade (such as a red wine marinade) instead. The best marinade for flat iron steak really depends on the flavors you enjoy.
Can you marinate flat iron steak too long?
Yes, you can marinate steak too long, including flat iron steak. According to the USDA, meat marinated longer than 48 hours may become mushy. This is because the marinade may over-tenderize the beef, breaking down the muscle fibers.
🥘 Flat Iron Steak Recipe Ingredients
Here’s your shopping list for sous vide flat iron steak:
- 1.5 lbs. flat iron steak or chuck steak (½-inch thick)
- 1 cup Italian dressing
- Steak seasoning
- 1 tablespoon butter
- Fresh parsley (for garnish, optional)
Get a printable recipe card at the bottom of the article!
I found flat iron chuck steak at Super Walmart. Don’t use a chuck pot roast (unless you feel like cutting it into thin steaks, that is).
Here is the kitchen equipment you need to make sous vide flat iron steak:
- Sous vide machine (or Ninja Foodi or Instant Pot with sous vide function)
- Ziplock gallon freezer bags (one for marinating, one for sous vide)
- Good knife
- Skillet
With a multipurpose cooker, there’s no need to keep a separate sous vide machine for sous vide cooking. Now it’s possible to make Ninja Foodi or Instant Pot sous vide steak. You can also sear the steak in these machines using the “saute” function, eliminating the need for a skillet.
Is flat iron steak tender or tough?
Flat iron steak is a tender cut of meat if the tough internal connective tissue was removed. It’s important that flat iron steak is cooked properly, so it doesn’t become tough.
🥶 Sous Vide Frozen Flat Iron Steak
Unlike most sources, I don’t recommend making sous vide frozen steak. Cooking frozen steak in the sous vide creates additional food safety risks that may lead to food poisoning.
According to the USDA, meat should not be left in the danger zone of 40-140F for longer than two hours. Sous vide frozen meat has a 10-25% increase in cooking time compared to fresh raw meat (source). Since we’re cooking the fresh steak at 130F for 2 hours, substituting a frozen steak would definitely break this food safety rule.
Of course, many of us break the food safety rules when cooking steaks anyway. The safe minimum internal temperature for steak is 145F (63C), or medium to medium-well (source). When we enjoy steak rare or medium rare, we’re not cooking the steak to a safe temp.
One of the tips on flat iron steak sous vide from Serious Eats is that “Steaks cooked under 130°F should not be cooked longer than two and a half hours at a time, for food-safety reasons.” That’s their rule, not one enforced by the USDA or FDA. If you’re pregnant or immunocompromised, I would modify this and other recipes to ensure your steak reaches 145F (63C) in under 2 hours.
⏲️ How to Make Flat Iron Steak in Oven
How long to broil flat iron steak? Broil flat iron steaks for 10-12 minutes in a preheated broiler, flipping halfway through cooking time. Use a meat thermometer to ensure the steak is the doneness you desire.
️🔥 How to Cook Flat Iron Steak on the Stove
Here’s how to pan fry flat iron steak:
- Marinate and season the steak as directed above. Heat 1-2 tablespoons of butter in a cast iron skillet over medium-high heat.
- Cook the steaks for 4-5 minutes per side, adding time as needed to reach your desired level of doneness. (Use a meat thermometer to check for doneness, not the appearance or color of the steak.)
- Let the steak rest for 10 minutes before slicing against the grain and serving.
❓ Can you overcook flat iron steak?
Yes, you can overcook a flat iron steak, but what counts as overdone depends on how you like your steak. IMHO, anything past medium makes the flat iron too tough. Here’s a steak doneness level chart:
Doneness | Color in Center | Temp (Fahrenheit) |
---|---|---|
Rare | Warm, red center | 120-125F |
Medium Rare | Red with some pink | 130-135F |
Medium | Pink | 140-145F |
Medium Well | A little pink | 150F |
Well Done (AKA Over Done lol) | No pink | 160F (just say no) |
😋 What is flat iron steak best used for?
You can serve flat iron steak with chimichurri, or make steak frites with air fryer frozen french fries. Flat iron steak is also good in steak fajitas, stir fry, and steak sandwiches. The intense beef flavor of this cut works well in a variety of dishes.
🌡️ Reheating Flat Iron Steak
Like other steaks, flat iron steak is best prepared and enjoyed fresh. If necessary, you can keep leftover flat iron steak in a covered container in the fridge for up to 3-4 days. Reheat steak in the microwave for 30-60 seconds on high.
You can also freeze leftover steak. Seal the steak in a freezer bag with the air pressed out to help prevent freezer burn.
📋 Flat Iron Steak Calories
One serving of sous vide flat iron steak has 437 calories, 4.3 grams net carbs, and 53 grams protein. This nutrition information includes half the marinade (since some is discarded), using a light Italian salad dressing. This flat iron steak recipe fits keto and other low carb diets.
FAQs
Can you sous vide flat iron 24 hours?
There’s no need to sous vide flat iron steak for 24 hours. You can have a perfectly tender flat iron steak in the sous vide in 2 hours or less.
Is a flat iron steak the same as flank steak?
Flat iron vs flank steak- what’s the difference? These steaks are not the same and come from different parts of the cow. The flat iron steak comes from the cow’s shoulder, while the flank steak covers the stomach of the cow.
Is flat iron steak the same as bavette?
Bavette steak is another name for flank steak. Bavette is not the same thing as a flat iron steak. These steaks come from different parts of the cow; bavette is near the hind quarter, while flat iron is from the shoulder.
What’s the closest thing to a flat iron steak?
Skirt steak and flank steak are the closest substitutes for flat iron steak.
How to cook air fryer flat iron steak?
Make a flat iron steak in the air fryer using this air fryer flank steak recipe. Simply substitute flank steak for a similarly-sized flat iron steak.
Can you cook flank steak sous vide?
Yes, you can sous vide flank steak! Substitute flat iron steak in this recipe for a flank steak of similar weight and thickness.
👨🏾🍳 Other Steak Recipes
Here are some other recipes for steak you may enjoy:
- Air Fryer Flank Steak
- Air Fryer Rib Eye Steak
- Steak Umms in Air Fryer
- Air Fryer Cabbage Steaks (AKA vegetarian and vegan steaks)
And if you’re looking for more sous vide recipes, don’t miss my Osso Buco sous vide. So delish!
Watch How to Make It!
Flat Iron Steak Sous Vide Recipe
Ingredients
- 1½ lbs. flat iron steak (680 grams), ½-inch thick (1.27 cm)
- 1 cup Italian salad dressing
- 2 tablespoons steak seasoning (or to taste)
- 1 tablespoon butter
Instructions
- Marinate flat iron steak in Italian dressing for 6-8 hours in the refrigerator. Put the steak and marinade in a food-safe gallon-size bag to marinate, and flip the bag every few hours.
- Remove the steak from the marinade, wiping away excess, and season both sides with steak seasoning.
- Put water in your sous vide machine. (I use 18 cups in my Ninja Foodi). Heat the water bath to 130°F (54°C).
- Place the seasoned flat iron steak in a clean gallon-size freezer baggie with a zip top. Alternatively, seal the food in a vacuum sealed bag using a vacuum sealer.
- To sous vide using a freezer bag, you need to make sure the air is pressed out. Put the food in the bag, and partially seal it while pressing out as much air as possible. Next, partially submerge the bag in the hot water, making sure the food is under the water level.When you partially submerge the baggie, the rest of the air should move out. Then you can finish sealing the bag and completely submerge it in the water. Be careful not to burn your fingers!
- If using the Ninja Foodi, put the lid on with the vent open to sous vide. Sous vide flat iron steak for 2 hours at 130°F (54°C).
- Heat the butter in a skillet over medium-high heat on the stove. After using the sous vide, sear the flat iron steak for 1-2 minutes per side (135°-140°F, medium-rare). Use a meat thermometer to ensure the steak has reached your desired doneness, adding cooking time as desired.
- Let the steak rest for 10 minutes before slicing and serving. Cut the flat iron steak against the grain into thin slices.
Notes
💭 Expert Tips from Dietitian Summer Yule
This is a level 3 recipe (weight maintenance and active lifestyles). Is flat iron steak healthy? Flat iron steak is a fairly lean meat that’s tender, flavorful, and has a good price. This red meat is packed with high-quality protein, zinc, and highly bioavailable heme iron. It’s a nutritional win in my book. The marinade adds a lot of calories to this entrée. Use a light Italian dressing to save calories without compromising flavor. If you’re pregnant or immunocompromised, you should modify this recipe for food safety. You want to get the steak to 145F (63C) in under 2 hours. Many of us eat medium rare steaks without issues, but this common practice creates an unnecessary risk to certain groups. Stay safe! Nutrition information is for one serving of sous vide flat iron steak. This nutrition information was calculated using half the marinade (since some is discarded), using a light Italian salad dressing.
nutrition info disclaimer
All recipes on this website may or may not be appropriate for you, depending on your medical needs and personal preferences. Consult with a registered dietitian or your physician if you need help determining the dietary pattern that may be best for you.
The nutrition information is an estimate provided as a courtesy. It will differ depending on the specific brands and ingredients that you use. Calorie information on food labels may be inaccurate, so please don’t sweat the numbers too much.
“To taste” means to your preferences, which may have to be visual to follow food safety rules. Please don’t eat undercooked food x
Nutrition
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Hello! I’m Summer, a registered dietitian and home chef who loves to cook, eat, and create recipes for you! Every recipe on this site has been tested by me to help ensure your success in the kitchen. All eaters are welcome here 🙂