Ingredients
For the Steak
- 2 pounds flank steak
- 1/4 cup avocado oil
- 1/3 cup fresh lime juice
- 1 tablespoon ancho chili powder
- 1 1/2 teaspoons ground cumin
- 1 1/4 teaspoons Mexican oregano
- 1 teaspoon smoked paprika
- 1 teaspoon granulated garlic
- 1 teaspoon onion powder
- 2 teaspoons Diamond Crystal kosher salt
For the Vegetables
- 1 large white onion, sliced into strips
- 1 red bell pepper, sliced into strips
- 1 yellow bell pepper, sliced into strips
- 1 green bell pepper, sliced into strips
- 1-2 serrano peppers, thinly sliced (optional)
For Serving
- 8 to 12 flour tortillas
- Sour cream, guacamole, salsa, shredded cheese
Marinate the Steak
In a large zip-top bag, combine the avocado oil, lime juice, and all the seasonings for the steak. Seal the bag and squish it around to mix everything together.
Add the flank steak to the bag, press out the air, and seal it. Massage the marinade into the meat. Refrigerate for at least 1 hour, but 4-6 hours is ideal for the best flavor penetration.
Remove the steak from the refrigerator 30-45 minutes before you plan to cook to let it come to room temperature.
Grill the Steak and Rest It
Preheat your grill to high, direct heat, aiming for 450-500F.
Remove the steak from the marinade, letting the excess drip off. Place it on the hot grates. You should hear a loud sizzle. Cook for ~4-6 minutes per side for medium-rare (130-135F internal).
Transfer the cooked steak to a cutting board and tent it loosely with foil. Let it rest for a full 10 minutes. This is a crucial step that allows the juices to redistribute throughout the meat.
Char the Vegetables
While the steak is resting, place a large cast-iron skillet directly on the grill grates (or on a stovetop burner over high heat). Add a splash of oil.
When the oil is shimmering, add the sliced onions and peppers. Cook, stirring only occasionally, for ~8-10 minutes. You want them to soften and develop a significant amount of char on the edges without turning to mush.
Slice Against the Grain and Serve
Look closely at the rested steak to identify the direction the muscle fibers are running. This is the “grain.” Use a sharp knife to slice the steak thinly across these lines, not parallel to them. Slicing against the grain shortens the muscle fibers, making the meat incredibly tender.
Serve immediately with the charred vegetables, warm tortillas, and your favorite toppings.
Cast Iron Steak Fajitas
Ingredients
For the Steak
- 2 pounds flank steak
- 1/4 cup avocado oil
- 1/3 cup fresh lime juice
- 1 tablespoon ancho chili powder
- 1 1/2 teaspoons ground cumin
- 1 1/4 teaspoons Mexican oregano
- 1 teaspoon smoked paprika
- 1 teaspoon granulated garlic
- 1 teaspoon onion powder
- 2 teaspoons Diamond Crystal kosher salt
For the Vegetables
- 1 large white onion sliced into strips
- 1 red bell pepper sliced into strips
- 1 yellow bell pepper sliced into strips
- 1 green bell pepper sliced into strips
- 1-2 serrano peppers thinly sliced (optional)
For Serving
- 8 to 12 flour tortillas
- Sour cream guacamole, salsa, shredded cheese
Instructions
- Mix the avocado oil, lime juice, and all steak seasonings in a large zip-top bag.
- Add the flank steak to the bag, seal it, and massage the marinade into the meat.
- Refrigerate for at least 1 hour or up to 6 hours for best flavor.
- Remove the steak from the refrigerator 30-45 minutes before cooking.
- Preheat the grill to high heat (450-500F).
- Place the marinated steak on the hot grates and cook for 4-6 minutes per side for medium-rare.
- Transfer the steak to a cutting board and tent with the foil. Rest for 10 minutes.
- While the steak rests, heat a cast-iron skillet on the grill with a splash of oil.
- Add the sliced onions and peppers to the skillet, cooking for 8-10 minutes until charred but still crisp.
- Slice the steak thinly against the grain.
- Serve the steak and vegetables with the warm tortillas and desired toppings.
