1. Cook sausage in a large heavy skillet over medium-high heat, stirring often, 3 to 5 minutes or until sausage crumbles and is no longer pink; drain, reserving 1/4 cup drippings in skillet. (If necessary, add melted butter to drippings to equal 1/4 cup.)
2. Sauté mushrooms and shallots in hot drippings over medium-high heat 4 to 5 minutes or until golden. Whisk flour into mushroom mixture, and cook over medium-high heat, whisking constantly, 1 minute or until lightly browned. Add chicken broth and sherry, and cook 2 minutes, stirring to loosen particles from bottom of skillet. Stir in sausage.
3. Gradually add half-and-half, and cook over medium heat, stirring constantly, 2 to 3 minutes or until thickened and bubbly. Stir in parsley and next 4 ingredients. Reduce heat to low, and cook, stirring occasionally, 5 minutes. Serve warm.