In a bowl, beat the egg yolk with the parsley and sparkling water.
Add the flour and cornflour and mix thoroughly with a fork.
Wash the potato skins and dip them in the batter then deep fry them for 3-4 minutes until they brown slightly. Don’t overcrowd the fryer. It’s better to fry in batches.
Drain on kitchen paper.
For the (herb) mayonnaise: mix the mayonnaise with chopped chives and parsley. Add curry powder to taste.