Preheat oven to 200°C. Grease a 32cm round 3.75L (15-cup) baking dish.
Cook gnocchi according to packet instructions, then drain and rinse under cold water.
Toss pumpkin and 2 tbs oil in a bowl. Combine with gnocchi, egg yolks, cream, nutmeg, ½ cup (50g) mozzarella, half the sage (including dried if using) and half the blue cheese. Spoon into prepared dish and top with remaining mozzarella.
Bake for 45-50 minutes or until pumpkin is tender.
Meanwhile, heat 4 tbsp oil in a frypan over medium-high heat. Add the nuts, remaining sage and cook for 1 minute or until crisp and bright. Remove using a slotted spoon and drain on paper towel, reserving oil. Put the nuts, fried sage and blue cheese into a container in fridge. Pour the sage oil into the pasta.
Top with nuts, fried sage and other half of the blue cheese.
