Wash the pumpkin, peel it, remove the seeds. Cut the pumpkin flesh into small cubes. Finely dice the onion.
Heat the oil in a large pan or in a wok, then sweat the pumpkin cubes with the onion and garlic for about 5 minutes. Season the tomatoes with basil, oregano, tarragon, salt, pepper and nutmeg.
Grease a baking dish and apply the first layer with the tomato sauce. Then put lasagne sheets on top. The next layer consists of pumpkin meat and a little mozzarella. Pour the rest of the tomato sauce over it.
Put another layer of lasagne on top and finish with a layer of pumpkin meat and the rest of the mozzarella. Bake the lasagna at 200 ° C on the middle rack for about 30 minutes.