Wash the potatoes and cook in boiling water for about 15 minutes. Drain, rinse and peel. Wash parsley and chervil, dab dry, put some chervil aside for garnishing.
Finely chop the rest of the herbs. Wash the fish, dab dry. Thyme wash, dab dry. Peel garlic. Heat clarified butter in an ovenproof pan. Add salmon, 2 stalks of thyme and garlic.
Fry the salmon for about 1 minute on each side. Season salmon with salt and pepper. Cook in the preheated oven (electric cooker: 100 °C/ convection oven: not suitable/ gas: not suitable) for 10-12 minutes.
Peel and slice the shallot. Crush the peppercorns. Boil up white wine, shallot, peppercorns, 1 thyme stalk and bay leaf, reduce by half over high heat. Pour through a sieve into a bowl.
Cut 150 g butter into small cubes and melt in the hot liquid. Beat the egg, egg yolks, cream, olive oil, lemon zest and juice in an ovenproof bowl over a hot water bath until foamy.
Slowly stir in a thin stream of butter mixture. Season with salt, pepper and sugar. Heat 25 g butter in a frying pan and fry the potatoes. Add parsley and chervil, season with sea salt.
Arrange salmon with potatoes and hollandaise sauce. Garnish with chervil and lemon zests.