Shuck the oysters and remove from their shell. Reserve the oyster liquor. Rinse the oyster.
To make the seaweed jelly: bring all the ingredients to the boil and strain. Add 1% agar to the liquid and turn to the boil. Remove from the heat and chill. When cold, blend in a food processor and place in a small squeezey bottle.
To pickle the seaweed: bring the cider vinegar, water and sugar to the boil. Remove from the heat and add the seaweed. Allow to cool. Keep in the fridge.
To make the oyster emulsion: blend the oysters and the oil together and season with sea salt. Pass through a fine sieve. Let down with a little water if it’s too thick. Place in a small squeezey bottle.
To plate: dress the oyster with oil and char with a blow torch. Season with sea salt. Lay the oyster on the plate and place a nice mound of emulsion beside it. Cover the emulsion with milled sea truffle. Dot the top of the oyster with seaweed jelly. Lay some pickled channelled wrack on top of the oyster. Garnish with some fresh nori and sea purslane.