This healthier version uses boneless skinless breasts instead of the traditional whole chicken spatchcocked. Chicken Alla Diavola means "Chicken in the style of the devil", which explains the heat from the hot pepper flakes.
Trim all of the fat from the chicken breasts. Gently flatten each breast between two sheets of plastic wrap using a cleaver to achieve uniform thickness. Arrange the chicken in a baking dish.
Combine lemon juice and mustard in a mixing bowl and whisk to mix whiskey in the oil pepper corns and pepper flakes poor the marinade over the chicken. Turn the breasts several times to marinade the chicken. Refrigerate for at least 30 minutes.
Preheat the grill to high. Oil the grate. Grill the chicken breasts until cooked, about 2 to 3 minutes per side, seasoning with salt and basting with any extra marinade.