Combine <quantity>50<unit>g</unit></quantity> of salt and <quantity>500<unit>ml</unit></quantity> of water. Whisk to dissolve the salt

Transfer the liquid to a baking dish and completely submerge <quantity>2<unit>fillets</unit></quantity> of turbot

Refrigerate for 20m to brine the turbot

Remove the filets from the brine, letting excess liquid drip off. Place them on a clean kitchen towel

Leave uncovered in the refrigerator 24h to air dry

Fill a pot halfway with cold water and add <quantity>½<unit>tbsp</unit></quantity> of salt. Add <quantity>200<unit>g</unit></quantity> of new potatoes

Place the pot over high heat and boil the potatoes for about 10m, until tender. Strain the potatoes and transfer them to a bowl with cold water to stop the cooking

Chop <quantity>⅓<unit>bunch</unit></quantity> of parsley very finely

Melt <quantity>2<unit>tbsp</unit></quantity> of butter in a pot over medium heat

Add <quantity>1</quantity> thinly sliced shallot. Sweat until it starts to soften but remains colorless, stirring occasionally

Add <quantity>1<unit>cup</unit></quantity> of white wine. Reduce it by half

Add <quantity>1<unit>cup</unit></quantity> of mushroom stock. Reduce it by half

Peel the potatoes and transfer them to a pot

Place the pot of potatoes over medium-high heat. Add <quantity>50<unit>ml</unit></quantity> of water and <quantity>3½<unit>tbsp</unit></quantity> of butter

Boil water in a pot with a steaming basket over medium heat

Place a fillet, on a piece of parchment paper, inside the steam basket. Cover it and steam for 12m, until the internal temperature reaches between <temperature>42<unit>°C</unit></temperature> and <temperature>45<unit>°C</unit></temperature>

Bring to a boil and stir constantly for approximately 5m, until the sauce gets creamy and emulsified. The water must be almost evaporated

Turn off the heat and add the chopped parsley. Mix well to coat all the potatoes. Season with salt to taste. The buttered parsley potatoes are ready

Add <quantity>50<unit>ml</unit></quantity> of heavy cream to the reduced wine and mushroom stock. Bring to a boil, then reduce the heat to low

Add <quantity>250<unit>g</unit></quantity> of cold butter cut into small cubes. Add one cube at a time, whisking constantly. Don't let it boil again

Remove from the heat and pass the sauce through a sieve

Season with sherry wine, sherry vinegar, and salt to taste. The sherry beurre blanc is ready

Warm a frying pan over high heat, and drizzle it with vegetable oil to taste

Add <quantity>100<unit>g</unit></quantity> of shiitake mushrooms and salt to taste. Fry until the mushrooms start to turn golden brown

Add <quantity>½<unit>tbsp</unit></quantity> of butter and sauté until the butter turns a nutty brown color

Transfer to a serving dish. The sautéed mushrooms are ready

Remove the turbot from the steam basket. Gently take the skin off with the help of a small offset spatula. Repeat the process with the second fillet. The steamed turbot is ready

Slice a piece of turbot and place it on a plate. Add the buttered parsley potatoes to taste

Add sautéed mushrooms to taste

Add <quantity>1<unit>tbsp</unit></quantity> of the sherry beurre blanc in the center of the dish

The steamed turbot with beurre blanc, potatoes & mushrooms is ready! Enjoy!