Prepare the Steak: In a small bowl, mix the chili powder, cumin, garlic powder, onion powder, smoked paprika, salt, and black pepper. Pat the steak dry, then rub it with olive oil and coat it evenly with the spice mixture. Let it rest for at least 20 minutes or refrigerate for up to 24 hours for a deeper flavor.
Make the Chipotle Crema: In a blender or food processor, combine the chipotles in adobo, Mexican crema, lime juice, onion powder, garlic powder, and cilantro. Blend until smooth. Taste and adjust seasoning as needed. Refrigerate until ready to serve.
Cook the Steak: Heat a large skillet or grill over medium-high heat. Add a bit of oil if needed, then sear the steak for 3-4 minutes per side (for medium-rare) or until it reaches your desired doneness. Remove from heat and let it rest for 5-10 minutes before slicing against the grain into thin strips.
Warm the Tortillas: Heat tortillas over an open flame, on a dry skillet, or in the oven until warm and slightly charred.
Assemble the Tacos: Place slices of steak onto each tortilla. Drizzle with chipotle crema and top with romaine lettuce. Add optional suggested toppings: avocado slices, queso fresco, pico de gallo, pickled jalapenos, and pickled red onions.
Serve: Garnish with fresh cilantro and optional lime wedges on the side. Enjoy!