1½ cups creme fraiche (to substitute, combine ¾ cup sour cream or buttermilk with ¾ cup heavy or whipping cream and refrigerate for 24 hours or put in a warm spot for several hours)
Simmer creme fraiche with sage and Marsala 5 minutes. Pour through strainer to remove sage. Add walnuts and asparagus and heat through. Toss with pasta. Season to taste. Top with Parmesan. Toss and serve.
