These slow cooker flank steak fajitas turn a lean cut of beef into fork-tender, shreddable meat that soaks up all the fajita flavor. The steak cooks low and slow with peppers, onions, garlic, and a homemade seasoning, then gets shredded back into the juices. It takes 10 minutes to load the pot, and the slow cooker does everything else.
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Why These Slow Cooker Steak Fajitas Work
Flank steak is lean and can turn chewy when cooked quickly past medium, but a long, gentle braise breaks down the muscle fibers until the meat shreds with a fork. Beef broth and a tablespoon of Worcestershire add savory depth, and the peppers and onions melt into a sauce that coats the beef.
- Tender, shreddable beef with almost no hands-on work.
- Big flavor from a simple homemade fajita seasoning.
- Perfect for tortillas, bowls, and nachos.
- Leftovers taste even better the next day.
Ingredients
The full amounts are in the recipe card below.
- 2 pounds flank steak, cut in half crosswise
- 2 bell peppers (red and green), sliced
- 1 large onion, sliced
- 3 garlic cloves, minced
- 1/2 cup beef broth
- 1 tablespoon Worcestershire sauce and 2 tablespoons lime juice
- Seasoning: 1 tablespoon chili powder, 2 teaspoons cumin, 1 teaspoon each smoked paprika and garlic powder, 1 teaspoon salt, and 1/2 teaspoon dried oregano
- Warm tortillas and toppings, for serving
Skirt steak or a small boneless chuck roast also works, since the meat gets shredded rather than sliced.
How to Make Slow Cooker Flank Steak Fajitas
Season the Steak
Mix the seasoning in a small bowl. Pat the steak dry and rub the seasoning on both sides. For extra flavor, sear the steak for 2 minutes per side in a hot skillet before it goes in the slow cooker.
Load the Slow Cooker
Put the steak in a 5- or 6-quart slow cooker and scatter the peppers, onion, and garlic over the top. Pour in the beef broth and Worcestershire sauce.
Cook Until Tender
Cover and cook on low for 6 to 8 hours, or on high for 4 to 5 hours, until the beef shreds easily with a fork. The USDA lists 145°F as the minimum for whole cuts of beef, and a long braise like this goes well past that until the meat is fall-apart tender.
Shred and Finish
Move the steak to a cutting board and shred it with two forks. Strain out the vegetables with a slotted spoon, and return the beef and vegetables to the slow cooker with a few spoonfuls of the juices. Stir in the lime juice and adjust the salt.
How to Serve Slow Cooker Steak Fajitas
Serve in warm flour or corn tortillas with pico de gallo, sour cream, cheese, and guacamole, or over rice as a burrito bowl. Try it with cilantro lime rice and black beans. For a taco spread, our ground beef taco bar has plenty of topping ideas.
How to Store and Reheat
Store leftovers with a little of the juices in an airtight container in the refrigerator for up to 3 days. Reheat in a skillet or the microwave until steaming hot. Freeze for up to 3 months and thaw overnight in the refrigerator.
Tips and Variations
- Cut the steak in half so it fits and cooks evenly.
- Add the peppers halfway through if you like them firmer.
- Add a can of drained black beans during the last 30 minutes.
- Stir in a chopped chipotle in adobo for smoky heat.
- Use chicken instead of beef and cook for a shorter time, like our slow cooker chicken fajitas.
- For a seared, grilled-style version, see our juicy steak fajitas recipe.
FAQ
What is the best cut of steak for slow cooker fajitas?
Flank or skirt steak is most common, but a boneless chuck roast also works because it shreds so well after a long cook.
How long does flank steak take in a slow cooker?
6 to 8 hours on low or 4 to 5 hours on high. It is done when the meat shreds easily with a fork.
Why is my flank steak tough?
It probably needs more time. Lean cuts get tender only after enough braising time, so keep cooking until it shreds.
Do I need to sear the steak first?
No, but searing adds a deeper, more roasted flavor. It is a good step if you have 5 extra minutes.
Can I cook it overnight?
Yes, on low. Start it before bed and it will be ready for lunch. Make sure your slow cooker switches to warm afterward.
Slow Cooker Flank Steak Fajitas
Ingredients
Main Ingredients
- 2 lb flank steak cut in half crosswise
- 2 bell peppers red and green, sliced
- 1 large onion sliced
- 3 garlic cloves minced
- ½ cup beef broth
- 1 tbsp Worcestershire sauce
- 1 tbsp chili powder
- 2 tsp ground cumin
- 1 tsp smoked paprika
- 1 tsp garlic powder
- 1 tsp salt
- ½ tsp dried oregano
- 2 tbsp lime juice
- warm tortillas and toppings for serving
Instructions
Cooking
- Mix the chili powder, cumin, smoked paprika, garlic powder, salt, and oregano. Pat the steak dry and rub the seasoning on both sides. Optionally sear 2 minutes per side.
- Place the steak in a 5- or 6-quart slow cooker. Scatter the peppers, onion, and garlic over the top. Pour in the beef broth and Worcestershire sauce.
- Cover and cook on low for 6 to 8 hours or on high for 4 to 5 hours, until the beef shreds easily with a fork.
- Move the steak to a cutting board and shred with two forks. Remove the vegetables with a slotted spoon.
- Return the beef and vegetables to the slow cooker with a few spoonfuls of the juices. Stir in the lime juice and adjust the salt.
- Serve in warm tortillas with your favorite toppings.
