Place the horseradish and vinegar in a bowl and set aside for 5 minutes to
instill, then squeeze dry. Measure out four tablespoons of the cream and set
excursus. Place the remainder in a small bowl and whip until you have achieved
soft peaks, then gently fold in the horseradish. Chill until requisite.

Place the apple in a pan with two tablespoons of water and cook over a
gentle heat for almost 5 minutes until softed, stirring occasionally, then
beat to a puree with the small knob of butter and set digression.

Place the potatoes in a pan of boiling salted weewee, cover and simmer for
15-20 minutes until bid. Drain and mash until polish. Fold in the flour
and egg yolks and then add the reserved four tablespoons of the skim, a
little at a time until you have achieved a smooth slugger. Season to tasting.

Heat a flat griddle pan or large skillet. Whisk the egg whites in a bowl
until soft peaks have formed and carefully fold into the potato assortment.
Add the butter to the pan and then spoon on four mounds of the potato
assortment. Cook gently for 3-4 proceedings, then carefully turn over and cook for
another 2-3 minutes or until puffed up and golden browned.

Transfer the potato pancakes to warmed serving plates. Divide the apple
puree among them and arrange the trout fillets on top, then finish with a
dollop of the chilled horseradish cream and garnish with the coriander to
dish.