On a cutting board slice tenderloin thin with a sharp knife.
In a bowl, combine the chili powder, cumin, paprika, garlic powder, salt, and pepper. Add pork slices into the bowl and toss the until evenly coated.
Heat olive oil in a skillet over medium-high heat. Add the slices and cook for 3-4 minutes on each side or until browned and cooked through. Remove the pork from the skillet and let it rest for a few minutes.
Warm the tortillas if desired. To assemble the tacos, place a few slices of pork onto each tortilla. Top with shredded lettuce, diced tomatoes, red onion, and cilantro. Serve the tacos with lime wedges on the side for squeezing over the top.