Preheat the oven to 160°C (320°F). Clean and cut the pumpkin and clean the potatoes. Place them in the hot oven for about 1 hour or until everything is soft (use a knife to find out).
Take bot out when ready and peel the potatoes while hot. Place potatoes and pumpkin in a large bowl and use a potato masher to mash it. Once mashed, let it cool. That way, most of the most will evaporate.
Once cooled down, add the egg, Parmesan and flour and mix with. If the dough still feels too sticky, add some more flour until it's good. You should be able to make a small ball of dough and it should stick too much to your hands. Add salt, pepper and muscat to your liking.
Divide the dough into five equal balls. Roll each ball out into a 2-3 cm wide rope. Cut it every 2 cm and roll the Gnocchi in the preferred shape (I used a fork). Place them on a baking sheet.
Once done, heat some salted water. Once it's boiling, reduce heat so it doesn't boil anymore. If it boils, the Gnocchi will fall apart. Add the Gnocchi and cook until they appear on the surface. Then skim them and drain in a sieve.
Heat the butter in a large frying pan. Once hot, add the sage and some salt. Fry for about 3 minutes, then add the Gnocchi and fry for another 3-5 minutes. Sprinkle some Parmesan over it and serve immediately.