Soak the morels in lukewarm water for about an hour. Rinse thoroughly.
Cut the flesh into small, narrow slices with a large, sharp kitchen knife.
Clean the leeks carefully, cut away the root end and cut into pieces about three centimeters long at the beginning of the length, then into fine strips (julienne).
Remove the skin from the onion and chop finely.
Heat the melted butter in a frying pan. Season the meat with salt and pepper and fry in portions briefly but heartily. Remove and keep warm.
Lower the temperature and add the cooking butter to the frying pan. Sauté the onions in it until translucent. Add the morels and leek strips and sauté for three to four minutes until soft.
Add the Noilly Prat and the white wine. Meanwhile, cook everything on medium heat for five minutes by a good third.
Fold in the cream, season the sauce and liven it up for two to three min. Next, add the meat repeatedly and just get well hot.