Green Lasagne With Shrimp Sauce

Preparation:

Preparation: Wash and shell the prawns, put the heads and shells in a saucepan with 20 cl of wine, 80 cl of water and an onion, a carrot and a stick of celery cut into slices. Add the bundle of tied aromatic herbs, a few grains of pepper and a little salt. Bring to a boil, skim off the skim and leave the fumet to cook over medium heat for 30 minutes. Finely chop the remaining vegetables and, separately, also cut the prawns into not too small pieces. Brown the vegetables in a saucepan with 60 g of butter, add the chopped prawns, salt and pepper. Then wet with a splash of wine, let it evaporate, then add about 40 cl of water in which you have dissolved the tomato paste. Cook the ragù over medium heat and covered for about 30 minutes. Filter the fish stock with a sieve, squeezing the shells and heads well. Toast the flour in a saucepan with 50 g of butter, add half a liter of fumet and cook the soup over low heat, stirring constantly, until it thickens. Boil the lasagne, a few at a time, in boiling salted water with a couple of tablespoons of oil, drain them with a slotted spoon and place them on a cloth. Spread a thin layer of the soup on the bottom of a buttered baking dish, make a first layer of lasagna, cover it with the prawn ragout and the soup. Repeat the same operations until all the ingredients are used up. Cover the pan with aluminum foil and put it in the oven at 200 degrees for about 30 minutes.