Sous Vide Asian Flank Steak (129°F / 54°C) – Soy & Sesame Marinade

Sous vide Asian flank steak is the perfect balance of tender and bold. Cook at 129°F (54°C) for 2 hours, then sear to caramelized perfection. The soy, sesame, and ginger marinade adds deep flavor to every slice—great for rice bowls or meal prep.

Updated October 2025 – Verified 129°F / 54°C for 2 hours, refined marinade ratios and sear instructions for best results.

This sous vide asian marinated flank steak is a straight mouthgasm. First off, sous vide flank steak is simply unbelievable. It is insanely tender and juicy with great flavor. The definition of perfection.

Then you add a marinade of soy sauce, sesame oil, ginger and garlic to the steak and you have the perfect flavor profile.

Do yourself a favor and make this recipe stat.

Packaging

An essential part of cooking sous vide is putting ingredients in an air-tight bag or container. The two most common techniques to package your ingredients are vacuum sealing and using the water displacement method.

A vacuum sealer removes all the air and seals the contents of a plastic bag through a vacuum. Ensuring the food is airtight and properly sealed prevents the bag from floating, which can result in uneven cooking. If you are in the market for a vacuum sealer, I’d recommend the Anova sealer.

The displacement method is a technique where you first place your food and marinades in a sous vide bag, submerge the bag in a container of water, and allow the pressure to force all the air out of the bag.

Both of these methods work for this recipe, so use whichever you feel more comfortable with!

Flank Steak Time and Temperature

Through loads of experimentation, we’ve found that cooking asian marinated flank steak at 54C/129F for 2 hours is the perfect combo. Cooking the flank steak for two hours break down the connective tissue (collagen), which results in extremely tender, juicy beef. Also, cooking the steak at a temperature of 129F ensures that the beef is a beautiful medium rare with great texture.

Just make sure you have a reliable sous vide that accurately regulates the temperature of the bath or your results may vary (check out the Anova or Joule).

Although this is our favorite time and temperature, we recommend you explore different combinations to find your personal favorite. Our cooking guide can always help you find your perfect time and temperature. 

Can You Sous Vide Frozen Steak?

The quick answer is, absolutely! Cooking frozen foods sous vide is an ultra convenient, safe way to prepare your protein. Just take the food directly from the fridge, repackage it (unless you know the bag is sous vide safe) and let the sous vide work its magic.

The only thing you’ll need to adjust is the cook time. If you are cooking frozen flank steak sous vide we recommend adding an additional hour to the cook time, so three hours total.

Best Way to Sear Beef After Sous Vide

Searing is the most critical step in the sous vide process. Getting a deep, rich sear can make your food look like it is Michelin star quality. Failing to do so will make your dinner guests wonder why they let you cook again.

If you want to get an amazing sear on your steak, you’ve got to:

1. Pat the meat completely dry with a paper towel
2. Season generously with salt or seasoning of your choice
3. Sear at extremely high temperatures.

First, pat the meat completely dry using paper towels. After the meat is dry, lightly brush the steak with olive oil then season generously with salt and pepper or a seasoning of choice. Note that brushing with olive oil is optional, but will allow the seasoning to stick to the meat better and results in a deeper sear.

At this point you want to determine the best searing method. For flank steak, we suggest pan searing, grilling or using a searing torch. The trick is getting the pan, grill or torch extremely hot, then searing for 1 to 2 minutes on each side. This results in a quick, high-quality sear without overcooking the steak.

Special Equipment

Sous Vide Machine – This one is obvious. To cook sous vide, you’re going to need a device to precisely regulate the temperature of the bath water. The two best sous vide machines in the game right now are the Anova Precision Cooker and the Breville Joule.

The main difference between the two is that with the Anova you can control the device both manually and with a mobile device, and with the Joule you can only control the device by using your mobile device. Either way, both sous vide machines are top class and you can’t go wrong with either choice.

12-quart Container – Although you can use a basic stockpot for your sous vide cooking needs, I highly recommend buying a large plastic container. They are inexpensive and spacious, so you won’t have to worry about cooking a big roast in a small pot. I recommend a 12 quart Rubbermaid container, as it is BPA free, sturdy, and large enough for just about anything you will be cooking.

Container Lid – If you are going to buy a plastic container, I highly suggest buying a compatible lid for it. When you sous vide for a long duration, the heat of the water causes evaporation. With a lid, it eliminates a majority of the evaporation so you can cook for hours care-free.

Cast Iron Skillet – If you are looking to take your searing game to the next level, we recommend investing in a cast iron skillet. By using a cast iron in this recipe, you’ll achieve a deep sear on the protein. Cast irons are also extremely handy for searing just about any and all sous vide meat. Lodge offers the best quality and price, which is why it is our favorite cast iron brand.

Next Level Sous Vide –Looking to take your sous vide skills to the next level? The Next Level Sous Vide eCookbook will push your culinary boundaries with 65 delicious recipes that are equally approachable and tasty. With pro tips and a detailed explanation of the sous vide process, you will be on your way to maximize your sous vide skills.

Check out our full list of recommended gear here.

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Sous Vide Asian Marinated Flank Steak

Course Main Course

Cuisine Asian

Keyword asian, beef, flank steak, marinated, sous vide, steak

Prep Time 5 minutes

Hands-On Cook Time 5 minutes

Sous Vide Time 2 hours

Total Time 2 hours 10 minutes

Servings 4 people

Ingredients

• 2 lbs flank steak
• ½ cup low sodium soy sauce
• 1 tablespoon toasted sesame oil
• 1 tablespoon ginger, grated
• 3 cloves garlic
• toasted sesame seeds, garnish
• green onions, sliced for garnish
• salt and pepper, to taste

Instructions

Preparation

1. Set sous vide machine to 54C/129F.

2. In a bowl, mix together soy sauce, sesame oil, ginger and garlic.

3. Put the flank steak in a freezer bag with the sauce mixture, and remove the air through a vacuum sealer or the displacement method. Drop beef in the bath for 2 hours.

Finishing

1. Remove bag from bath. Take steak out of the bag, pat dry and lightly season with salt and pepper to taste. 

2. Heat a large skillet on high and add oil. Sear for 1 to 2 minutes on each side. Remove from pan and place on plate to rest. Garnish with sesame seeds and green onions, serve and enjoy!