handful cilantro (about 1/3 cup packed), roughly chopped
1 jalapeno, thinly sliced or minced (optional)
1 cup thinly sliced cabbage
cotija cheese (optional)
juice of 1 orange (about 1/4 cup)
juice of 2 limes (about 2 tablespoons, plus additional lime wedges for serving)
1 tablespoon minced garlic
1 teaspoon salt
1 teaspoon cumin
1 teaspoon chili powder
1/3 cup oil
Whisk together all marinade ingredients. Pour into a large resealable bag. Add steak, seal the bag, and shake a bit to get the steak well-coated. Refrigerate 8 hours or overnight.
Grease a large skillet and bring to temperature over medium-high heat. Add steak (discard marinade) and cook 4-6 minutes on each side, til slightly charred on the outside. Remove from heat and allow to rest for about 5-10 minutes. (meanwhile move on to next step)
Combine diced onion, cilantro, and jalapeños (optional) in a bowl and stir to combine. Set aside.
Assemble tacos by dividing cabbage, avocado slices, and onion mixture between tortillas. Thinly slice the steak and divide between tacos. Serve with lime wedges and top with crumbled cotija cheese if desired.