whisk in egg then sparkling water just until combined with small lumps remaining
shake excess buttermilk from chicken then lightly dust with 0.25 cup all purpose flour
dip chicken into batter and let excess drip
fry in batches 6 to 8 minutes total turning once until deep golden and chicken reaches 165 F
drain on rack and season with salt
serve hot with lemon and dipping sauce.
Notes
1. Keep batter ingredients very cold. Do not overmix the batter. Maintain oil at 350 F and do not overcrowd. Substitute club soda for sparkling water. For extra crunch add 0.5 cup panko to a dry dredge and press after battering