Heat a medium nonstick skillet over medium-high heat. Add EVOO and brown the sausage, breaking it up with the back of a spoon. Transfer sausage to a paper towel-lined plate.
Add the onion and garlic to the pan. Cook over moderate heat until tender but not brown. Add the wine and return the sausage to the skillet, then continue to cook a couple of minutes. Add the chicken stock, heavy cream, sage and pumpkin. Bring up to a bubble and simmer until thick, a couple of minutes. Add the pasta and cheese and season with the nutmeg. Toss to coat the pasta with the sauce. Taste and check seasoning, adding salt and pepper to taste.
Serve the pasta garnished with a sprinkle of chives.