Soak porcini mushrooms in 1/8 l warm water for 20-30 minutes. Clean mushrooms, wash if necessary, chop coarsely. Peel onion and garlic and chop finely. Chop the nuts coarsely. Wash the sage, dab dry and remove the leaves.
Cut 4-6 leaves into fine strips, put the rest aside for garnishing.
Cook the pasta in boiling salted water according to the instructions on the packet.
Pour the porcini mushrooms into a sieve lined with kitchen paper, collecting the soaking water. Rinse porcini briefly, then chop them coarsely.
Heat the oil in a frying pan. Fry the ham in it until crispy. Fry all mushrooms, onion and garlic for about 5 minutes. Season with salt and pepper. Fry the nuts and sage briefly. Add mushroom water and bring to the boil.
Cut the gorgonzola into small pieces and melt it with half of the ricotta.
Drain the pasta. Fill with the mushroom mixture and place in a greased casserole dish with the opening facing upwards. Spread any remaining mushroom mixture around the noodles. Stir the rest of the ricotta and milk until smooth.
Season to taste with salt and pepper. Drizzle over the noodles. Bake in the preheated oven (electric cooker: 200 °C/recirculating air: 175 °C/gas: level 3) for 12-15 minutes. Garnish with remaining sage leaves.