Cook the pasta in boiling salted water for about 10 minutes. Wash, clean and halve the mushrooms. Fry briefly in hot fat. Season with salt and pepper. Drain noodles and chill in cold water.
Drain well. Peel and finely dice the shallots. Remove mushrooms from the pan. Sauté the shallots in the frying fat. Add cream and stock and bring to the boil. Stir in sauce thickener Wash dill, dab dry and chop.
Add to the sauce. Season the sauce with lemon juice (keep 2 tablespoons), salt and pepper. Rinse salmon cold and pat dry. Cut into cubes. Sprinkle with remaining lemon juice and salt.
Put the pasta, salmon and mushrooms in an ovenproof dish. Pour sauce over it. Drain the mozzarella and cut into slices. Spread the mozzarella and parmesan on the casserole dish and bake in a preheated oven (electric: 200 °C/ gas: level 3) for 20-25 minutes.