Step 1

Place chicken breasts on a work surface and cover with waxed paper. Pound each breast with the smooth side of a meat mallet to an even thickness. Sprinkle both sides with oregano, onion powder, and salt.

Step 2

Heat olive oil in a large cast iron skillet over medium heat. Add chicken breasts and cook for about 4 minutes. Flip and cook about 3 minutes longer. Top each breast with sliced mozzarella. Cover the skillet and cook until cheese has melted and chicken is no longer pink in the center and the juices run clear, 2 to 3 minutes longer. An instant-read thermometer inserted into the center should read at least 165 degrees F (74 degrees C).

Step 3

Remove from the skillet and allow to cool for 1 minute before serving.