Place the fish in a food processor and pulse until smooth.

Add the butter and combine well.

Grind the fish and butter very finely twice.

In a bowl over crushed ice add the eggs and beat with a spatula until very cold.

Stir in as much cream as necessary.

Season to taste.

Shape the mousse into quenelles, using two spoons and set on strips of greased parchment paper.

Poach or steam until firm, about 5 minutes.

Place on serving dishes or plates and coat with the shrimp sauce.

If desired, place under the grill or salamander to give a browned glaze.