Bring a large pot of salted water to a boil. Add the tortellini and cook according to label directions. Reserve 1/2 cup of cooking water, then drain the pasta.

Meanwhile, heat the butter in a skillet over medium high heat. Add the shallot and cook, stirring, until slightly softened, about 2 minutes. Add the pumpkin and nutmeg and cook, stirring, for 1 minute. Stir in the cream and bring to a low boil. Reduce the heat to medium low and simmer, stirring, until slightly thickened, about 5 minutes. Stir in the cheese and cook until thick, about 1 minute more. Season to taste with salt and pepper.

Add the tortellini to the skillet and toss with the sauce, adding the reserved cooking water to loosen the sauce if necessary. Divide among four bowls and top with more cheese and the parsley. Serve.