Soak both slices of bread in the milk for 5 minutes. Flake the crab meat, put it into a bowl, chop the shrimp and add them to the crab.
Separate the eggs and set the whites aside. Add the yolks, mustard, Worcestershire sauce, almonds, cayenne pepper, and mayonnaise to the crab. Rinse, dry, and chop enough parsley to give 1 tbsp. and add it to the bowl.
Squeeze the bread dry, add it to the crab mixture, and stir until soft but not sloppy. Add some bread crumbs if the mixture is too moist.
To make the coating, put the flour onto one plate and the breadcrumbs onto another. Whisk 1 tbsp. of water into the egg whites. Divide the crab mixture into eight portions and shape them into cakes. Dip the crab cakes into the flour, shake off the excess, then dip them into the egg whites, and coat with the bread crumbs.
Heat 1cm of oil in a large skillet over a fairly high heat. Fry the fish cakes for 2–3 minutes on each side until they are crisp and golden, then drain them on paper towels and serve two per person.