Slow cooked in a heat-regulated water bath, this sous vide flank steak is incredibly tender, and comes out perfect every time. The flavorful steak is finished with a quick sear, and served with a delicious, easy chimichurri sauce.
What Makes This Recipe So Good
- Trying the sous vide method to cook flank steak will give you the most juicy, tender and delicious steak. By cooking it slowly, submerged in a temperature-controlled water bath, you’ll never overcook this lean cut of beef, resulting in perfect results every time. Never dry, never chewy.
- We finish the cooking process of the flank steak with a quick reverse sear to get nice crust, and serve it with a super flavorful chimichurri sauce. Keeping the seasoning simple to let the flavors of the steak shine, and keep this recipe very easy.
- Flank steak is super versatile. It’s a great cut to use in salads or tacos. Or it can be served with a variety of sides, from these cheesy mashed potatoes, air fryer sweet potatoes, roasted asparagus to sautéed mushrooms.
- When cooking the flank steak sous vide, make sure the zip-top bag with the meat is fully submerged in the water bath. If it tries to float, the bag might still have too much air in it, so double-check you removed as much air as possible before cooking.
- Allow the flank steak to rest for at least 5 minutes before slicing, so it gives the natural juices time to settle. Talking about slicing, you’ll always want to slice a steak against the grain to get the best texture. Cutting against the grain means cutting the meat in the opposite direction of the meat fibers. If you look at the steak closely, you’ll see tiny lines going in one direction, and you’ll want to slice across them.
- We cook the flank steak in a water bath set at 130° Fahrenheit, which will result in a medium-rare steak. If you prefer a rare steak, you can set the water between 125° and 127° Fahrenheit. For medium, set between135° to 139° Fahrenheit. And for well done, 140° to 145° Fahrenheit.
- For the chimichurri, always use fresh herbs and a good quality extra-virgin olive oil for the best tasting sauce. If you don’t love olive oil, avocado oil will work great too.
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For the Flank Steak
- 1 flank steak 1 ½-2 pounds
- salt to taste
- freshly ground black pepper to taste
- 1 tablespoon neutral oil avocado oil, olive oil, etc.
- Sous vide immersion circulator
- Large pot or other large, heat-resistant container
- Cutting board or plate
- Paper towels
- large food-safe vacuum sealing bag or large sealable food-safe plastic bag
- vacuum sealer optional, see Notes for alternative
- Food processor
- Large skillet
- Spatula optional
- Fill large pot or other large, heat-resistant container with water. Insert sous vide immersion circulator and set to 130° Fahrenheit. Note: pot must be deep enough that water level falls between minimum and maximum indicators on circulator.
- Place flank steak on cutting board and pat completely dry on all sides with paper towels. Generously season all sides with salt and black pepper, then place flank steak in large sealable food-safe bag.
- Place garlic cloves in food processor. Pulse until garlic is finely chopped, then add fresh parsley and fresh cilantro. Continue pulsing until herbs are finely chopped, then add olive oil, lemon juice, dried oregano, red pepper flakes, and salt. Pulse again until ingredients are fully combined and chimichurri sauce forms.
- Add half of prepared chimichurri to bag with flank steak. Refrigerate other half of chimichurri until ready to serve.
- Remove as much air from bag as possible with vacuum sealer or water displacement method (see Notes) and seal bag completely. Once water is preheated to 130° Fahrenheit, place sealed bag in pot, making sure flank steak is fully submerged in water. Cook for 2 hours.
- After 2 hour cook time, heat large skillet over medium-high heat. When skillet is warm, add neutral oil. Swirl pan occasionally to coat in oil and continue heating pan until oil is hot and shimmery.
- Remove flank stank from bag and place on cutting board. Use spatula to gently scrape chimichurri off flank steak, then place steak in skillet. Sear steak 1 to 2 minutes, or until golden brown, then flip steak over and sear other side 1 to 2 minutes or until golden brown.
- Transfer seared flank steak to cutting board or large plate. Set steak aside to rest 5 minutes, then carve steak into thin slices, top with remaining chimichurri sauce, and serve with desired sides.
- Water Displacement Method: If you don’t have a vacuum sealer, place flank steak in an appropriately-sized sealable food-safe bag and seal the bag halfway across the top. Heat the water with the sous vide immersion circulator as instructed, then slowly lower the half-sealed bag into the heated water. The temperature difference outside the bag will force the air out of the bag – you should see the plastic cling to the meat. Once the food is entirely submerged and the air is all out, seal the bag completely and continue with the recipe.
Number of total servings shown is approximate. Actual number of servings will depend on your preferred portion sizes.
Nutritional values shown are general guidelines and reflect information for 1 serving using the ingredients listed, not including any optional ingredients. Actual macros may vary slightly depending on specific brands and types of ingredients used.
To determine the weight of one serving, prepare the recipe as instructed. Weigh the finished recipe, then divide the weight of the finished recipe (not including the weight of the container the food is in) by the desired number of servings. Result will be the weight of one serving.