Combine the chili powder, cumin, paprika, garlic powder, salt, and pepper in a small bowl. Sprinkle the spice mixture over the slices of pork, toss until evenly coated.
Remove the pork from the skillet and let it rest for a few minutes. I like to top mine with shredded lettuce, diced tomatoes, red onion, and cilantro. Lime juice is a must, too!