1. Open the scallops and place the nuggets in cold water for a few minutes.
2. Reserve the beards.

Make the stock

1. Sweat the scallop beards until colored, add the aromatic garnish.
2. Deglaze with the white wine, reduce by half and add the water.
3. Cook for 20 minutes; strain and set aside.

Make the Jerusalem artichoke purée

1. Cook 400 g (14 oz.) Jerusalem artichokes in just enough milk to cover.
2. Once cooked, drain, reserving the liquid.
3. Purée in a thermomix or blender until smooth.

Prepare the sea urchins and broth

1. Open the sea urchins, reserving the juice, coral and tongues.
2. Crush the shells, brown them and add enough water to cover.
3. Cook for 20 minutes.

Making the white wine pastry.

1. Combine the flour, white wine, salt and squid ink to make a firm dough.
2. Roll out to a thickness of 1 mm.
3. Divide the dough into 2 equal parts and fold the first part over the second.
4. Cut the pastry using a 4 cm round cutter.
5. Fry in 180° C (350° F) oil.

Prepare the garnish

1. Sweat the spinach, drain and set aside.
2. Cut the Jerusalem artichokes into 2 cm thick pieces. Hollow out the centre using a melon baller or Parisian scoop so that they can be stuffed.
3. Cook the Jerusalem artichokes in boiling water with a pinch of salt.

Make the sauce

1. Reduce the stock and cream by half.
2. Add the lemon juice, Jerusalem artichoke purée and butter.
3. Strain.

Make the foam

1. Combine all the ingredients in a saucepan.
2. Bring to a boil; strain.
3. Place in a soda siphon and charge with a gas cartridge.

Make the sea urchin jelly

1. Bring 300 ml (1 1/4 cups) of sea urchin broth to a boil with the agar agar.
2. Pour the mixture into a stainless steel baking sheet to obtain a 2 mm thick jelly.
3. Unmold, cut into 4 cm squares and set aside.

Sear the scallops

1. Hollow out the white wine pastries and fill them with the siphon mixture.
2. Glaze the Jerusalem artichoke pieces, stuff them with spinach and arrange.