Rub the salmon steaks with salt and pepper. Sprinkle the salmon with some of the lemon juice. Place the steaks under a preheated grill; count on about 3-4 min. per side. Clean the mushrooms and cut them into slices. Fry the peeled and chopped shallot until translucent in the hot butter. Add the mushrooms and braise them in about 5 min. until tender. Add salt, pepper and the rest of the lemon juice. Let the moisture evaporate as much as possible and then add the cream and the very finely chopped herbs. Place the salmon on preheated plates and divide the sauce. Delicious with a rosette of mashed potatoes.