Spinach, Peppers, and Steak Fajitas with Avocado Crema

1. Combine the soy sauce, canola oil, 1 tablespoon of the lime juice, brown sugar, cumin, garlic powder, and chili powder in a zip-top plastic bag. Add the steak, seal the bag, and set aside at room temperature for 30 minutes or in the fridge up to overnight. (Remove from the fridge 30 minutes before cooking.)

2. Meanwhile, combine the avocado, sour cream, remaining 2 tablespoons lime juice, cilantro, jalape‏ño (if using), and salt in a food processor and blend until smooth. Cover and set aside.

3. Heat a grill with one side over high heat and one side over medium. Set a large cast iron or other heavy skillet on the medium side. (Alternatively, set a grill pan over high heat and the skillet over medium heat on the stove.)

4. Remove the steak from the marinade and put it on the hot side of the grill (or in the grill pan). Pour the remaining marinade into the skillet and add the bell peppers and onion. Cover and grill 2 minutes. Flip the steak, stir the veggies, cover, and cook another 2 minutes. Continue until the steak is cooked to your liking, about 120°F for medium-rare and 130°F for medium, 8 to 10 minutes. Remove the steak to a cutting board, cover, and rest for 10 minutes. (It will continue to cook as it sits.)

5. Heat the tortillas according to package directions or directly on the grill (or grill pan). Keep warm.

6. Add the spinach and corn to the skillet with the veggies and cook, stirring frequently, until the peppers are tender and slightly charred, 3 to 5 minutes more.

7. To serve, cut the steak across the grain into thin strips. Divide among plates with the mixed vegetables and 2 tortillas. Fill the tortillas and dollop with the avocado crema. Sprinkle with additional cilantro, if desired.