Cut the skate off the bone (reserve bones for parsley sauce recipe) and vacuum seal it in a bag with the salt brine. Leave to brine in the bag for 24 hours.
Take the fish out of the bag and rinse it in clean water. Revacuum it with the vinegar and water and poach at 45°C for 25–30 minutes, depending on the size. Cool down in iced water.
When it is completely cooled down remove from the bag and peel the fish in segments, using your fingers to pull it apart and keep only the thickest and juiciest parts. Allow about 30-35g
Rinse the bones thoroughly and pat dry.
Place in a pan with plenty of oil and fry them until golden.
Transfer to a pot with the wine and water and heat to about 95°C.
Leave to steep for 20 minutes, strain bones and leave liquid to cool.
Pick and clean the parsley and spinach and blanch them until very soft in boiling salted water.
Cool down, dry and blend with the cooled down skate bouillon.
Pass through a fine sieve until very smooth. Season with salt.
Clean the mussels well. Steam them in the white wine for about 20 minutes. Strain liquid and mussels. Remove steamed mussels from shell and reserve for mussel and celeriac recipe. Reduce mussel liquid to half.
Cool down and freeze. Leave to hang on a strainer for 1-2 days slowly defrosting and clearing out.
Mussel and Celeriac
Ensure the steamed mussels are patted dry. Finally, mix in the lemon juice and olive oil to taste.
Combine them with the lemon juice, mustard and salt and blend to a purée.
Add the oil while blending to form an emulsion. Pass through a fine sieve to smooth out.
Clean and scrub the celeriac without peeling it. Rub with salt and wrap in tin foil.
Bake at 200°C for about an hour and leave to cool down.
Remove skin and grate the celeriac on a box grater to obtain the juicy strands.
Add a bit of the emulsion to the celeriac and season with more lemon juice if needed.
For each person put two spoonfuls of the celeriac on a plate then carefully build the strands of the skate around the celeriac.
Brush the fish with the mussel glaze.
Pour a good amount of the parsley purée onto the plate with the fish.
Sprinkle with a small amount of olive oil and serve.