Perch with Asparagus, Pistachio and Chervil Beurre Blanc

Last weekend finally, finally, the first local strawberries have arrived among the first green asparagus. Heavenly! Okay, the strawberry spent some time under foil, but still it is local and I couldn't resist any longer! Anyway, back to the asparagus! I absolutely love love love to eat green asparagus raw, especially when it is so tender like these. Originally, I planned to serve it simple with poached egg and parmesan, but then I had the idea to combine it with pistachio and prepare a light starter with perch and some confit potatoes.

Ingredients:
for the chervil e beurre blanc:
1 shallot
10 g butter
4 tablespoons white wine
1 teaspoon white wine vinegar
250 ml fish stock (optional)
150 g ice cold butter
50 g chervil
só, bors
for the asparagus:
100 g green asparagus
50 g pistachio
30 g grape seed oil
1-2 teaspoon sherry vinegar
salt, pepper
for the confit potatoes:
1 large potato
clarifed butter
salt
you'll also need:
1 perch fillet per person
50 g dried black trumpet mushroom
butter and oil for frying

In a small saucepan melt butter, add chopped shallot, wine, vinegar and stock. Bring to the boil and reduce until there is about 1/4 of the liquid left. Whisk in the cold butter chervil with a help of a blender. Season with salt and pepper. Cut asparagus in thin slices and set the spears aside. Puree pistachio with oil and mix with the raw asparagus slices. Season with sherry vinegar, salt and pepper. Cut potato in any shape you like, but it shouldn't be bigger than 2-3 cm. Melt clarifed butter and heat until it reaches 75-80°C then add the potatoes and leave it there for about 15-20 minutes by constant temperature. Season before serving and sprinkle with finely ground pistachio. Fry asparagus heads and mushroom in butter, season.