Four Cheese Tortelloni with Asparagus and Prosciutto

3 medium shallots, thinly sliced
1/4 C olive oil
2 1/2 C asparagus tips (cut from 4 bunches asparagus stalks)
4oz thinly sliced prosciutto, cut in thin strips
1/2 C heavy cream
1 (8.9oz) bag four cheese tortelloni
1/4 C fresh grated Parmigiano Reggiano

Cook shallots in oil in a large skillet over low heat until golden, about 5 minutes. Add asparagus tips and prosciutto and cook, stirring occasionally, 4 minutes more. Add heavy cream; bring to a boil and simmer 1 minute. Season with salt and pepper to taste. Cook tortelloni in large pot of salted water until al dente, about 10-11 minutes. Drain and toss with sauce, cheese and salt and pepper to taste.