Tusk fillet with herbs:
Rinse and dry the fish well.
Sprinkle it with salt and let it sit at room temperature for 30 minutes.
Rinse the salt off the fish and dry it well. It is now ready for use.
Peel and chop the onions and garlic.
Peel the carrots and chop them into small cubes.
Wash and grate the lemon and then squeeze out the juice. Set both aside.
Rinse the dill thoroughly and dry it well. Then chop it coarsely.
Rinse the fennel, cut off the top and discard it. Also, cut the fennel into small cubes.
Heat a sauté pan with oil.
Once the oil is hot, add a pat of butter, and sauté the vegetables over medium heat until slightly soft. Do not overcook them as they will also go into the oven. Season with salt and pepper.
Place the fish in an ovenproof dish and lightly season it with salt and pepper. Sprinkle with grated lemon zest and dill, and finally drizzle lemon juice over it.
Lay the sautéed vegetables on top of the fish in the dish.
Pour in the white wine.
Bake the fish in the oven for about 25 minutes at 200 degrees Celsius (392 degrees Fahrenheit).
Hollandaise Sauce:
Start by clarifying the butter.
Put the butter in a small pot and melt it over low heat.
Once the butter is melted, skim off the whey from the top. The whey is the white, cloudy layer on the surface of the pot.
Carefully pour the clarified butter into another pot - make sure the sediment does not transfer.
Place the egg yolks and fish stock in a bowl that can withstand sitting over a water bath.
Whisk until the mixture becomes light and foamy.
Add the clarified butter - start with a little at a time while whisking, then you can add the rest of the butter in a thin stream. Whisk the sauce constantly.
Season the sauce with lemon juice, salt, and white pepper.
Serving:
Boil the potatoes until they are tender.
Cut off the bottom part of the green asparagus and steam them in lightly salted water.
Serve the fish along with potatoes, green asparagus, and the delicious Hollandaise Sauce.