For the fish, dissolve 50 g salt in 1/2 l cold water and soak the fish in it for about 15 minutes. Wash the lemons hot and dab dry. Grate the zest of 2 lemons. Mix with 2 tablespoons of oil.
Meanwhile peel the cucumber and cut off approx. 10 thin cucumber slices all around with a wide economy peeler. Sprinkle with salt, place in a freezer bag, close and let it stand for about 10 minutes.
Chop the rest of the cucumber finely. Squeeze the lemons. Puree cucumber pieces and lemon juice, except for 2 tbsp. Then pour through a sieve, collecting the juice.
Lift the fish out of the brine, dab dry and brush with 1 tablespoon of lemon oil. Place in a frying tube, close and cook in a hot water bath (at approx. 56°C) for approx. 16 minutes.
In the meantime, preheat the oven (electric cooker: 200°C/circulating air: 175°C/gas: level 3). Wash the potatoes and cut them into slices. Mix with 1 tablespoon of oil, rosemary and thyme on a baking tray. Season with salt and pepper.
Bake in the oven for about 20 minutes.
Crumble the bread for the vegetable garnishes. Melt 2 tablespoons of butter. Fry the bread crumbs until crispy. Peel, wash and cut carrots into pieces. Wash the asparagus, cut off the woody ends and cut into pieces.
Blanch both in a little salt water for 4-5 minutes. Sort and wash the sprouts.
For the butter foam, melt 80 g butter until brown. Allow to cool a little, then pour through a fine sieve. Whisk the egg white in a hot water bath (at approx. 70 °C) for 5-10 minutes until a kind of mayonnaise is formed.
Season with salt and 2-3 tablespoons lemon juice.
Cover the fish pieces with Löjrom and dill and wrap each with 5 cucumber bands. Arrange and pour the cucumber-lemon juice over them. Add potatoes, vegetables, breadcrumbs and butter foam in small bowls.