Wash, clean and slice the porcini. Peel pumpkin, remove seeds. Cut the flesh into small cubes. Wash, clean and cut tomatoes into small pieces. Peel and finely dice onion and garlic.
Grate the lemon peel. Wash the thyme and dab dry. Set half aside for garnishing. Remove the thyme leaves from the rest. Cook the pasta in boiling salted water according to the instructions on the packet. In the meantime heat 2 tablespoons of oil in a large frying pan.
Add porcini mushrooms and sauté for about 3 minutes, remove and season with salt. Put the pumpkin into the pan and cook for about 4 minutes while turning. Add onion, garlic and tomato pieces and cook for another 3 minutes.
Add tomato paste and sauté briefly. Drain the pasta, collecting about 150 ml of pasta water. Add pasta water, mushrooms and thyme to the sauce and bring to the boil while stirring. Season to taste with salt, pepper, sugar and lemon peel.
Arrange noodles and sauce on plates, garnish with thyme.