Season the plaice with salt and dust with flour.
Fry the plaice in half the butter for 90 seconds on the presentation side then 45 seconds on the other.
Remove the fish from the pan and let it rest for two minutes.
Sauté the samphire in the remaining butter for 3 minutes until tender.
Combine the white crab meat with herbs, capers, and chopped eggs in a bowl.
Mix in enough olive oil to allow the mixture to form a quenelle.
Adjust the seasoning of the white crab mixture with lemon juice if desired.
Sweat the shallots and garlic in butter for 3 minutes until softened.
Whisk in the brown crab meat and white wine and bring to a simmer.
Simmer for one minute to reduce then whisk in the mayonnaise off the heat.
Season the sauce with salt and pepper to taste.
Place samphire on plates and top with a plaice fillet.
Top the fish with a white crab quenelle and drizzle the brown crab sauce around the edge.