Place the chicken on a large cutting board and cut in half horizontally to create two thin pieces of chicken. (You can skip this step if you're using thin cut chicken breasts).
Cover the chicken with plastic wrap and gently pound with a meat mallet to thin to 1/6"- 1/4" thick. Sprinkle both sides with salt and pepper. Set aside.
Prepare 3 separate bowls for breading: Beat the eggs and milk together and add to a shallow bowl. Add the flour to a second shallow bowl. Add the Panko, garlic powder, onion powder, chili powder, ground cumin, and dried oregano to a third shallow bowl and mix to combine.
Heat 4 tablespoons of olive oil in a large skillet (or cast iron skillet) over medium heat. The oil should be between 360°F -375°F.
Dredge one chicken breast in flour, then dip it into the egg mixture. Make sure to let the excess egg wash fall back into the bowl. Finally, dip the chicken into the Panko mixture. If your skillet is large enough to cook 2 pieces of chicken at once, bread 2 chicken breasts.
Transfer the breaded chicken to the pre-heated oil and sauté for 3-4 minutes per side, or until the internal temperature reaches 165°F. Remove and transfer to a cooling rack on top of a cookie sheet.
Repeat with the remaining chicken breasts, adding extra olive oil as needed.
Garnish with cilantro and serve with lemon slices. Enjoy immediately for best results.