Peel, deseed and cut pumpkin into medium sized chunks. Steam for 15 minutes or roast until soft, then mash. (If steaming, make sure pumpkin is well drained).
Place mashed pumpkin and all gnocchi ingredients in a mixing bowl.
Using a spatula, mix all ingredients until well combined to form a soft dough. The dough should be slightly sticky but can be easily formed into a ball.
Sprinkle a generous amount of flour onto a kitchen bench or large wooden chopping board. Place dough in the center and sprinkle with more flour so you can easily roll and shape the dough into log.
Divide the dough into 4 equal pieces (so each piece is more workable size).
Bring a large pot of salted water to the boil.
While the water is boiling, begin rolling the dough into ropes, approx. 2cm in diameter, then cutting into gnocchi portions, each one approx. 2-3cm in length.
Optional: Use your thumb to roll each gnocchi over a floured fork. Place on tray.
Add gnocchi into the pot of boiling water, avoiding overcrowding.
Once they begin rising to the top (approx. 1 minute), drain or use a slotted spoon to drain and transfer to a bowl.
Melt butter in a large pan over medium high heat. Add in sage, then add gnocchi and toss gently for 2-3 minutes, you may need to cook the gnocchi in batches until they are golden and crispy, and butter is slightly browned.
Serve immediately with a generous amount of freshly grated parmesan, and squeeze half a lemon over gnocchi to dress.