Fish quenelles with sauce dieppoise

Bring the water, butter and salt to a boil in a saucepan.

Off the heat beat in all the flour at once until incorporated, then return to moderately high heat and cook a couple of minutes until it forms a mass.

Off the heat beat in the whole egg quickly, then the egg white, working fast so the egg does not set.

Transfer the pate a choux to a bowl and chill.

Skin the halibut and cut it into one inch strips.

Put the fish strips, the chilled pate a choux, the salt and the white pepper into a food processor with two tablespoons of cream and run it about 30 seconds.

Scrape down and blend in more cream a tablespoon at a time while the mixture is stiff; it must still hold its shape in a mass on a spoon.

Poach a test spoonful in barely simmering salted water for several minutes and taste; process in more cream only if it can be absorbed, and better too little than too much.

Chop a tablespoon of truffle and blend it into the mixture.

Bring seafood stock or salted water to a bare simmer in a wide 12 inch pan.

With two spoons dipped in very cold water, scoop the mixture, transfer the spoon to the other hand and smooth the top with the inverted bowl of the second wet spoon, then slip the quenelle into the liquid.

Poach 15 to 20 minutes; they double in size and are done when they roll easily.

Lift them out with a slotted spoon onto a paper-towel-lined plate, then transfer to a buttered dish.

Heat the oven to 350F to warm the quenelles through.

Blend the egg yolk with a quarter cup of cream and set aside.

Cook the butter and flour together until they foam, add three quarters of a cup of the poaching liquid and the milk, and boil one minute.

Beat the hot sauce by droplets into the yolk and cream to temper, return it to the pan and boil another minute, stirring.

Season with salt, pepper and a couple of drops of lemon juice, then strain.

Plate with the sauce and finish with chopped parsley.