Flank is one of the leanest cuts of beef, but because of its leanness, it’s also one of the toughest cuts. That’s why it’s often sliced thinly and used for dishes like steak fajitas.
Is there a way to make it more tender though? Let’s try it with this Sous Vide Flank Steak recipe.
- Related article: Best Sous Vide Steak Cuts
Sous Vide Flank Steak Recipe
- Sous Vide Cooker
- Sous Vide Container
- Vacuum Sealer
- Vacuum Seal Bags
- Cast Iron Skillet
- Metal Pot
- 14 Ounce Beef Flank (400g)
- 1/2 Onion
- 5 Basil Leaves
- 2 Garlic Cloves
- 1 tbsp Chopped Dried Rosemary
- 14 Ounces Tomato Purée (400g)
- 1 tbsp Butter
- 5 Sage Leaves
- 1 tbsp Paprika Powder
- 1 tbsp Curry Powder
- 3 tsp Salt
- Set the sous vide cooker at 52°C / 125.6°F. While the water heats, we'll first prep the beef flank with a good sear.
- Take a cast iron skillet and heat it over high heat. Once it's very hot, place the flank on it and sear all sides to lock in the juices.
- Don’t let it cook for a long time. 30-60 seconds on each side should be enough.
- Once the water it heated, put the beef inside the vacuum seal bag and seal it. No need to add other ingredients into the bag.
- Cook the flank for 30 hours.In the meantime, we can prepare the tomato sauce.
- Place a pot over medium heat.
- Finely chop the 1/2 onion. When done, add 2 tbsp of olive oil and the chopped onion inside the pot. Fry over low heat for 2minutes.
- Add the peeled garlic cloves and basil leaves. Also pour in the tomato purée.
- Let it cook for 15 minutes over the lowest heat possible.
- After 15 minutes, we have a tomato sauce that's almost ready. It still needs to be spiced and seasoned.
- Now add everything else. Add the butter, sage leaves, paprika powder, curry powder, dried rosemary, and the 3 tsp of salt in the tomato sauce.
- Let it cook for another 2 minutes. Test the sauce and if it tastes a bit acidic, add 1 tsp of sugar to compensate and remove the acidity.
- When done, take it off the stove and keep refrigerated until the flank is done.
- Once the meat is perfectly cooked, you just need to slice it down and serve glazed with our spiced tomato sauce.
Flank Steak Cut
The flank steak is a cut of beef that runs along the side of the animal, and it’s often used for making steaks because they’re relatively inexpensive and readily available.
The flank cut is lean and lots of meaty flavor. It’s also a commonly used muscle, so that leads to it being tough and chewy.
Besides sous vide, it can be cooked on the grill or in a pan. Steak fajita dishes most often use flank steak for the dishes.
Vacuum Sealing the Flank Steak
Sous vide cooking requires that you use an airtight bag in the water bath in the sous vide container. Vacuum sealing works well for this purpose.
You should also make sure that your food is submerged in enough liquid to fully cover the food. If you’re in the market for a new vacuum sealer, I suggest the Anova. This machine is easy to operate and accommodates different bag sizes for various food sizes. It also includes an app that allows you to monitor the water temperature as you cook.
If you don’t have a vacuum sealer handy, you can also use a ziplock freezer bag and use the water displacement method to get the air out of the bag.
Flank Steak Time and Temperature
As flank steak is a tough, lean cut of beef, it’s best to have longer cook times to tenderize them.
It’s best to sous vide flank steaks around 125° to 135°F for 2-35 hours. I’ve found that the longer I cook the flank steak filet, the more tender it is.
To break down the tough, connective tissue, you’ll need to cook it for 2-3 hours at least.
Through my cooking experiences, 129°F at 30 hours gives me the most tender, medium-rare flank steak I’ve ever had.
Sous Vide Frozen Flank Steak
Sous vide is a great way to make sure your meat stays juicy and tender. You can easily prep frozen meats ahead of time and then cook them right away.
To ensure safety, you should always use bags specifically designed for sous vide. Don’t forget to add an extra hour to the cook time if you’re using frozen meat.
Read more about how to sous vide from frozen.
How to Sear Flank Steak After Sous Vide
Searing is the most critical part of cooking steaks and getting the nice crust that locks in the beef flavor and juices. Getting a great sear on your flank steak is easy too.
- Pat dry the meat thoroughly with a paper towel
- Season well with salt or seasonings of your choice
- Sear the steak on each side for 45-60 seconds with a kitchen torch or skillet at extremely high temperatures.
First patting the flank steak dry will make sure you are not drying and cooking the steak further. If the steak is already dry on the outside, the sear process will only be searing then.
If the steak is wet on the outside, the sear process will also be drying the wetness, which will also end up cooking the steak, which you don’t want.
Check out other great sous vide steak recipes: