Chicken Cordon Bleu

Preheat oven 375 degrees F. Place flour in a shallow dish. Whisk egg, mustard and pepper in another shallow dish. Place panko in a third shallow dish.

Cut a horizontal slit along the thin, long edge of a chicken breast, nearly through to the opposite side. Open up the breast and place 2 slices of ham and 1 slice of cheese in the center. Close the breast over the filling, pressing the edges firmly together to seal. (Secure with toothpicks, if desired.) Repeat with the remaining chicken breast. Sprinkle the chicken with salt. Hold each stuffed breast together and dip in the flour, then in the egg mixture, and then dredge in the breadcrumbs. (Discard leftovers.)

Heat oil in a large skillet over medium-high heat. Add the chicken and cook, turning once, until browned on both sides, 2 to 3 minutes per side. Transfer the chicken to a baking sheet; bake until no longer pink in the center or until an instant-read thermometer inserted into the thickest part registers 170 degrees F, about 30 minutes. Cut each chicken breast into 2 portions and serve.