Place each chicken breast half between two pieces of plastic wrap. Pound lightly into a rectangle about 1/4 to 1/8 inch thick. Remove plastic wrap. In a shallow bowl, combine the flour and salt. Coat chicken breasts with flour mixture. Sprinkle chicken breasts with lemon pepper.
In a 12-inch skillet cook the chicken breasts in the hot butter, half at a time, over medium-high heat for about 3 minutes on each side or until brown and no longer pink. Remove chicken from skillet. Add lemon slices to skillet; cook for 2 to 3 minutes or until lightly browned, turning once. Return all of the chicken to the skillet, overlapping chicken breasts slightly. Drizzle lemon juice over the chicken breasts. Cook for 2 to 3 minutes more or until pan juices are slightly reduced. Serve chicken, lemon slices, and pan juices over hot cooked rice or pilaf, if desired. Makes 6 servings.