The fish is marinated usual, familiar to many way. But for those who never did describe in a nutshell. Fish should be cleaned and split into fillets. Each rump roast cut into desired pieces and put in a bowl (preferably glass), shifting each layer with onion rings and peas of pepper. Then add the Bay leaf and pour the cooled to room temperature with the marinade of water, sugar, salt and vinegar. Put in the fridge at least a day.

When the fish is ready to eat, make the sauce. For this cooked yolks well triturated with sugar and mustard (with 1 yolk, but then I realized that I should add another).

Then drop by drop add the vegetable oil and RUB well with a spoon. It is important not to add too much oil at a time, otherwise it will come and no force will force it to blend with the mustard into a homogeneous mass. Will have to add mustard, followed by all the rest *WALL* . Add the dried tarragon (if fresh is to put twice as much), lemon juice and salt to taste.