1 kg russet or other floury potatoes, scrubbed
2.2 kg butternut pumpkin (squash) , cut into eighths and seeds removed
Rock salt, as needed
12/3 cups (250g) plain flour, plus extra for dusting
250 g cornflour, plus extra if needed
250 g Grana Padano, freshly grated
1 cup (250ml) water
100 g unsalted butter
24 sage leaves
300 g gorgonzola dolce, diced
Preheat the oven to 180°C.
Place the potatoes and pumpkin on a bed of rock salt on a baking tray and bake for 1–1.5 hours or until a wooden skewer can be inserted into a potato without any resistance. Remove from the oven, cut the potatoes in half and immediately press, flesh-side down, through a potato ricer, onto a clean, dry workbench, lightly dusted with extra flour, spreading it out on the bench. Remove the pumpkin skin and press the flesh through the ricer onto the potato. Leave to cool for a few minutes.
Sift the combined plain flour and cornflour over the top, sprinkle with 200 g of the Grana and fine salt to taste and break the eggs into the centre. Using a pastry scraper and your hands, work the mixture until the dough just comes together; don’t overwork it, add a little more cornflour if it’s too moist.
Shape the dough into a 4 cm-high brick, cut lengthways into 1 cm-thick slices. Cut each slice into 1 cm-thick strips and roll gently with your hands to form logs. Cut the logs into 1 cm-thick pieces.
Bring a large heavy-based saucepan of salted water to the boil. Add the gnocchi and cook for 1–2 minutes or until they rise to the surface.
Meanwhile, combine the water, butter and sage leaves in a heavy-based frying pan over medium heat. As the gnocchi rise to the surface, scoop them up with a slotted spoon, drain well and add to the frying pan. Gently toss for a couple of minutes to coat well.
Remove from the heat, add the gorgonzola and remaining Grana and continue tossing until the cheese has melted. Transfer to a platter or divide among plates and serve.