In a large skillet, heat the olive oil over medium heat. Add the shredded chicken, chili powder, cumin, garlic powder, onion powder, salt, and black pepper. Stir to combine and cook for about 5 minutes, until heated through and fragrant.
While the chicken is heating, warm the corn tortillas in a separate skillet over medium heat for about 30 seconds on each side, or until pliable.
To assemble the tacos, place a generous portion of the seasoned chicken on each tortilla. Top with diced tomatoes, shredded lettuce, diced red onion, and chopped cilantro.
Squeeze fresh lime juice over the top of each taco and sprinkle with queso fresco if desired.
Serve immediately with additional lime wedges on the side.