Cut the pumpkin into cubes. Pour into a small saucepan and add just enough water to just cover the cubes. Bring to the boil and cook softly at a low temperature for about 10 minutes.
Meanwhile cook the noodles al dente and drain in a colander.
Put the pumpkin cubes and the stock in a small bowl, set aside.
Heat the olive oil in the saucepan. Finely chop the chilli pepper and clove of garlic and fry in hot oil. Add the ginger, nutmeg and paprika powder and fry for a short time, then deglaze with the pumpkin cubes and the stock. Stir in sour cream, cream, cheese, pumpkin seed oil, salt and pepper. As soon as the cheese is completely melted, puree the sauce and season again with spices.
Arrange the pasta with the sauce on plates and serve sprinkled with chopped walnuts.
If you don`t like it fiery, replace the chilli pepper with a finely chopped, half red pepper and replace the hot paprika powder with a mild one. I am not stingy with spices for this dish, as the pumpkin flesh swallows a lot, as do the nuts.