These amazing Flank Steak Tacos can be made in the Instant Pot or the slow cooker, and the tacos are delicious with Spicy Mexican Slaw. Use low-carb tortillas or eat the spicy flank steak in lettuce wraps for a low-carb or Keto meal, and the tasty tacos are also dairy-free!

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Low-Carb Flank Steak Tacos finished tacos on serving plate

These amazing Flank Steak Tacos are perfect to make in the Instant Pot or the Slow Cooker and you’ll find instructions here for either method. And the zesty shredded beef tacos are such a winner served with my favorite Spicy Mexican Slaw!

I haven’t cooked flank steak too much, and it’s not the cheapest cut of beef you could use for tacos, but I loved the flank steak tacos because the flank steak shredded apart just the right amount, and the flavor was great too. For the cooking sauce I added flavor by using both green and red salsa, and I love these tacos with a healthy squeeze of lime! 

I hope you’ll try making the tasty Flank Steak Tacos in the Instant Pot or the Slow Cooker, whichever you prefer. You will love these tacos, I promise! 

What ingredients do you need?

How did I make the Flank Steak Tacos lower in carbs?

I made the recipe low-carb by using my favorite Mission Carb Balance Tortillas and making sure to choose salsa without added sugar. For a Keto version that’s even lower in carbs, go easy on the slaw and use lettuce wraps for serving. And of course if you don’t care about low-carb just use any tortillas you prefer.

What if you don’t like cilantro?

If you’re not a cilantro fan just use more thinly sliced green onion for the Spicy Mexican Slaw!

Love Your Instant Pot?

I use a 6 Quart Instant Pot (affiliate link) for all the recipes I make using an Instant Pot, although in this recipe you can see photos of the Cuisinart Electric Pressure Cooker I started out with! Check out my growing collection of Instant Pot Recipes! You can find lots more Instant Pot or Slow Cooker Recipes on my other site!

Pressure Cooker (or Slow Cooker) Low-Carb Flank Steak Tacos process shots collage

How to make Instant Pot Flank Steak Tacos:

(Scroll down for complete recipe, including slow cooker instructions and nutritional information.)

  1. Cut up onion and measure the spices. 
  2. Turn the Instant Pot to SAUTE, MEDIUM, add the olive oil, and cook the onions for a few minutes, then add the spices and cook about a minute more.
  3. While onions cook trim the flank steaks and cut in half both lengthwise and crosswise.
  4. Add the flank steak, tomato salsa, and Herdez Salsa Verde (affiliate link) to the Instant Pot.
  5. Set to MANUAL, HIGH PRESSURE, 45 minutes. Use natural release for 15 minutes, then quick-release to release the remaining pressure.
  6. Use a slotted spoon (affiliate link) to fish out the pieces of meat, leaving the sauce in the pressure cooker. (You can cook off some of the water if you think the sauce looks too thin.)
  7. Let meat cool for a few minutes on a cutting board, then shred it apart with two forks. Put meat back into the pressure cooker and stir to combine with the sauce.
  8. Make half the recipe of Spicy Mexican Slaw (or other slaw of your choice that would be good with spicy taco meat.)
  9. Heat a cast-iron frying pan and use it to warm one tortilla at a time; then fill the tortillas with some meat and slaw. (I like Mission Carb Balance Tortillas for this recipe.)
  10. Serve the tacos with extra lime and Green Tabasco Sauce (affiliate link) to add at the table if desired. I like them with a lot of lime!

Flank Steak Tacos on plate served with spicy Mexican Slaw and lime wedges

More Low-Carb Dinners with Mexican Flavors:

Low-Carb and Keto Mexican Food Dinners ~ Kalyn’s Kitchen

Ten Low-Carb Mexican Food Favorites ~ Kalyn’s Kitchen

Low-Carb Mexican Food Dinners to Make in the Instant Pot ~ Slow Cooker or Pressure Cooker

Weekend Food Prep:

This recipe has been added to a category called Weekend Food Prep  where you’ll find recipes you can prep or cook on the weekend and eat during the week!

Flank Steak Tacos on plate served with spicy Mexican Slaw and lime wedges
Yield: 8 tacos

Flank Steak Tacos

Prep Time 15 minutes
Cook Time 45 minutes
Additional Time 15 minutes
Total Time 1 hour 15 minutes

Flank steak gets spicy and tender in the slow cooker or Instant Pot, and then you make it into these amazing Flank Steak Tacos with Spicy Mexican Slaw. Choose low-carb tortillas for a low-carb meal, or eat the tacos in lettuce wraps if you prefer for Keto.

Ingredients

Flank Steak Ingredients:

  • 1 onion, chopped
  • 2 T olive oil
  • 1 tsp. ground cumin
  • 1 tsp. chili powder (see notes)
  • 2 lbs. flank steak
  • 1 1/2 cups Herdez Salsa Verde
  • 3/4 cup Pace Picante Sauce

Other Ingredients:

  • 8 Mission Carb Balance low-carb tortillas, taco size
  • 2 cups thinly-sliced green cabbage
  • 1 cup thinly-sliced red cabbage
  • 1 green onions, thinly sliced
  • 1/4 cup chopped fresh cilantro (see notes)
  • 2 T mayo (or more, to taste)
  • 1 1/2 T fresh-squeezed lime juice (more or less to taste)
  • Green Tabasco Sauce, to taste
  • Vege-Sal to taste (or use regular salt)
  • extra limes for serving (optional)
  • Green Tabasco Sauce for serving (see notes, this is definitely optional)

Instructions

Instant Pot Instructions:

  1. Peel the onion and chop into smallish pieces. Measure the cumin and chili powder.
  2. Heat the oil in the pressure cooker on SAUTE setting, medium heat, add the onions and cook 2-3 minutes or until they start to soften, then add the ground cumin and chili powder and cook about a minute more.
  3. While onions cook, trim visible fat from the flank steak and cut each steak lengthwise and then again crosswise. (I cut it so the shredded pieces of meat wouldn’t be too long to eat easily in a taco.)
  4. Add the flank steak pieces to the pressure cooker with the red and green salsa, lock the lid in place, set to MANUAL  HIGH PRESSURE, 45 minutes. You can use the quick release method to release the pressure, but if you have time I recommend doing 15 minutes natural release and then quick release.
  5. Use a slotted spoon to scoop out the meat, leaving the sauce in the pressure cooker. (Some brands of salsa have more water than others; if you think the sauce looks too thin you can turn the pressure cooker to SAUTE and cook off some of the liquid.)
  6. Let the meat cool for a few minutes on the cutting board, then use two forks to shred the meat apart and put it back in the pressure cooker. Stir meat to combine with the sauce and keep warm.
  7. When the meat is almost done, make Spicy Mexican Slaw (or other slaw of your choice) to serve with the tacos.
  8. When you’re ready to eat, heat tortillas one at a time in a dry frying pan until the tortilla is hot and softened (cast iron pans are best for this.)
  9. Fill the tortilla with desired amount of saucy beef on one side and slaw on the other side and fold over to eat. Serve hot, with lime and Green Tabasco Sauce to add at the table if desired.
  10. Extra taco meat can be frozen or kept in the fridge for several days and reheated in a small pan or in the microwave. This meat can also be used for burritos, beef enchiladas, lettuce wraps, or taco salad.

Slow Cooker Instructions:

  1. Use ingredients as above, but reduce the amount of salsa verde to 1 cup and the amount of red salsa to 1/2 cup.
  2. Brown onions and spices in a frying pan on the stove and transfer to slow cooker. While onions brown, trim the meat as above.
  3. Add a little more oil to the frying pan and brown the pieces of meat on both sides. (Browning will add flavor for the slow cooker, highly recommend doing this.)
  4. Cook on low for 6-8 hours or on high for 3-4 hours, or until the meat shreds apart easily.
  5. Remove meat from the slow cooker as above and shred apart, then put back into slow cooker. (If there seems to be too much liquid in the slow cooker, you can put it in a pan on the stove and simmer to reduce, but generally the shredded meat will absorb the liquid when you add it back into the slow cooker.)
  6. Put meat back into the slow cooker on warm setting (or low) and prepare slaw and tacos as above.

Notes

I used ground Ancho chile powder, Herdez Salsa Verde (which didn’t have added sugar), Pace Picante Sauce (which didn’t have added sugar), and Mission Carb Balance Low-Carb Tortillas for this recipe.

I serve the tacos with my favorite Spicy Mexican Slaw and Green Tabasco Sauce. (Links are affiliate links.) If you're not a cilantro fan, just use more thinly sliced green onion in the spicy slaw!

Beef taco meat recipe was adapted from The Easy Pressure Cooker Cookbook.)

Nutrition Information:

Yield:

8

Serving Size:

1

Amount Per Serving: Calories: 353Total Fat: 17gSaturated Fat: 5.3gTrans Fat: 0gUnsaturated Fat: 9.9gCholesterol: 94mgSodium: 667mgCarbohydrates: 14gFiber: 3.9gSugar: 5.8gProtein: 35g

Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations. Nutrition calculations for this recipe was done using net carbs for the low-carb tortillas.

Did you make this recipe?

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Pressure Cooker (or Slow Cooker) Low-Carb Flank Steak Tacos thumbnail photo

Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
You need to use low-carb tortillas like the ones I used if you’re making these tacos for any type of low-carb diet or the original South Beach Diet. If you don’t find the tomato salsa and salsa verde I used, be sure to buy the brand with the least amount of sugar you can find. I would recommend using lettuce wraps if you want the recipe to be Keto or gluten-free, and Flank Steak Tacos in lettuce wraps would also work for any phase of the original South Beach Diet.  The tacos would be phase two or three for the original South Beach if made with tortillas.

Find More Recipes Like This One:
Use Instant Pot Recipes to find more recipes like this one. Use the Diet Type Index to find recipes suitable for a specific eating plan. You might also like to Follow Kalyn’s Kitchen on Pinterest to see all the good recipes I’m sharing there.

Historical Notes for this Recipe:
This recipe was posted in 2016. It was last updated with more information in 2022.

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