Peel the onions and garlic and dice them finely. Clean the mushrooms, possibly wash and slice them. Clean, wash or peel the soup greens and cut into fine cubes. Wash herbs, shake dry and chop leaves or needles finely.
For the ragout mince in 2 portions in a hot large pan without fat crumbly sear. Fry onions, herbs, garlic, vegetables and mushrooms briefly. Season with salt, pepper and porcini mushroom powder. Stir in the tomato paste and sauté briefly. Pour juice on the tomatoes. Mash tomatoes lightly with a wooden spoon. Stir in 100 ml water. Simmer the minced sauce for about 6 minutes.
Bring 3-4 l salted water (1 teaspoon salt per litre) to the boil. For the béchamel sauce, melt butter in a saucepan, stir in flour and sauté. Stir in the milk bit by bit. Simmer for about 2 minutes while stirring. Season with salt, pepper and nutmeg. Whisk eggs and 2 tablespoons of cold water. Stir into the béchamel in a thin stream. Remove from the heat and season with salt, pepper and nutmeg.
Cook pasta in salted water according to package instructions until al dente. In the meantime, preheat the oven (electric cooker: 200 °C/recirculating air: 180 °C/gas: see manufacturer). Grate cheese. Approximately 1⁄4 Put the béchamel in an ovenproof dish with a high rim (approx. 20 x 30 cm). Drain the pasta, rinse with cold water and drain.
Place about half of the pasta in the mould, preferably pointing in one direction. Spread half of the minced meat ragout on top. Place about 1⁄4 sauce on top, sprinkle 1⁄4 cheese over it. Pour the rest of the noodles, ragout, sauce and cheese on top. Bake in a hot oven for about 45 minutes.