Mix the coral of the spider crab in the thermomix with the shellfish water. Strain and set aside.
Cut the king prawn and sauté. Make an infusion with olive oil at 70ºC for 60 minutes. Strain and set aside.
Cut the bread crust, cut the bread and mix with the king prawn oil. Strain and set aside.
Rehydrate the gelatin and boil together with the green peppercorn and the shellfish water. Beat with the kitchen aid on an ice bath. Put the resulting foam in a square mold and let it set in the fridge for an hour. Cut the foam in rectangles of 6 cm de long and 3 cm wide. Place the cress in the square.
Fill up a mold (same as the foam) with the seasoned seafood. Place the breadcrumbs on top and on one side the foam and finish with some sauce.
Restaurante Akelare, San Sebastian - www.akelarre.net