In a small metal bowl, mix the plankton and water together until smooth.
Brush the plankton slurry onto the matsutakes, allow the slurry to dry slightly and repeat with a second brushing of plankton.
Once the matsutakes are well coated, dry at room temperature for 4 hours, or until the slurry is completely dry.
Slice thinly on a mandolin, about five perfect slices per mushroom. Hold between parchment paper in the refrigerator.
Reserve the remaining slurry for garnishing the plate.
Roast the marcona almonds in an oven set at 325° F (163° C) for 10 minutes, or until golden brown and fragrant. Reserve 10 almonds and put the rest in a pressure cooker.
Add to the pressure cooker 800 grams (3 1/3 cups) of water and run a high pressure cycle for 30 minutes.
Strain the liquid from the almonds and put into a blender top, reserving the liquid separately. Add the crème fraiche and mix on high for 1 minute, or until smooth.
Add some of the cooking liquid from the almonds if the puree is not turning freely in the blender. Season with maldon salt and strain through a chinois into a bowl set over an ice bath. Once cool, place in a squeeze bottle.
Streak the plankton slurry on a plate in a random order. Place a few dots of the puree and put a couple of toasted almonds on the puree. Lay five slices of the matsutakes on the puree. Garnish with the ice lettuce.