Chop the chicken into small, uniform half-inch pieces and place them in a bowl.
Mix the meat with olive oil, chili powder, cumin, paprika, garlic powder, oregano, salt, and lime juice until well coated. Let sit for 15 minutes.
Heat a cast-iron skillet over medium-high heat until very hot.
Sear the meat in a single layer without stirring for 3 to 4 minutes to develop a crust. Stir and cook for another 3 to 4 minutes until done.
Warm the corn tortillas in a dry skillet until pliable.
Serve the meat on warm tortillas, topped with diced onion and cilantro, with lime wedges on the side.