From Rachael Ray Every Day, May 2017
Working with 1 breast at a time, butterfly the chicken by cutting horizontally with a sharp knife almost all the way through. Open like a book and pound between sheets of plastic wrap to 1/8- to 1/4-inch thick. Season the chicken with salt, pepper, and the oregano.
In a medium bowl, mix the lettuce, tomatoes, cucumber, herbs, feta, olives, onion and pepperoncini. Drizzle the Greek salad with the lemon juice and about 2 tablespoons EVOO; season.