Pre-heat the oven to 425°F.
Split the pumpkin and scoop out the seeds. Rinse and dry the seeds and arrange them on a small baking sheet. Drizzle the pumpkin with a light layer of EVOO and season liberally with salt and pepper. Roast the pumpkin until very tender. Scoop the pumpkin flesh out and add to a food processor and puree until smooth.
Heat a large pot of water to boil; salt the water and cook the pasta to al dente.
Meanwhile, heat 1 tablespoon EVOO, a turn of the pan, in a large skillet over medium-high heat. Add the sausage to pan, brown and crumble it, then add the shallots and garlic and cook until tender, 3-4 minutes. Add the sage and deglaze the pan with the wine. Stir the pumpkin into the pan and thin out the consistency with chicken stock to form a sauce, then season with salt, pepper and freshly grated nutmeg, to taste. Reduce the heat to low and stir in the cream, a couple of turns of the pan.
Reserve a little starchy cooking water before draining the pasta. Drain the pasta and add it to the sauce; use the reserved starchy cooking water if the mixture gets a little too tight. Top the pasta with cheese and serve.