Whisk together lime juice, olive oil, minced garlic, cumin, chili powder, smoked paprika, oregano, salt, and pepper in a bowl. Submerge your steak for 2-4 hours to marinate.

Preheat your grill to high heat, or heat a cast-iron skillet over medium-high.

Remove the steak from the marinade 10 minutes before cooking. Sear each side for 4-6 minutes until desired doneness is reached.

Let the steak rest for 5 minutes before slicing it against the grain into thin strips.

Spread refried beans on tostada shells. Add lettuce, tomatoes, and onions, followed by carne asada strips, cheese, crema, avocado, and cilantro.