Place the trout fillets, head-to-tail, next to each other, skinned side on a tray and season. Soak the gelatine leaves in a little cold water until soft, then lay over one of the trout fillets, and place the other trout fillet on top, so that both are still head to tail. Roll the combined fillets in the chopped herbs, then wrap in cling film, twisting the ends to make a sausage-like shape. Poach in boiling water for 15 minutes, remove from the water, then chill in fridge overnight.
Cook the new potatoes in boiling, salted water for approximately 10 minutes. Once cooked, drain and allow to cool. When cool, cut the potatoes into 2cm dice and mix in the chopped herbs, crème fraîche, a little lemon zest and seasoning.
Place the cucumber and capers into a food processor and blitz to a purée. Add the dill, season and mix in mayonnaise to a ketchup consistency.
For the fritters, first bring the milk to the boil, add the butter and allow to melt, then add the flour and mix to a thick paste. Continue mixing until the paste cools, then add the egg yolks and beat until the mixture leaves the sides of the pan. Add the shrimps and combine into the mixture. Chill for 1 hour, then roll into small balls approximately ½cm in diameter. Deep-fry the fritters for 2 minutes at 180°C, until golden brown. Drain and keep warm.