Melt butter in a large skillet over medium-high heat; add next 3 ingredients, and sauté 2 minutes or just until tender. Remove from heat. Stir in broth, brandy, and mustard, and return to heat. Bring to a boil, and cook, stirring occasionally, 12 minutes or until mixture is reduced by half.
Stir together cream and cornstarch until smooth. Add cornstarch mixture to sauce, and cook, stirring constantly, 2 minutes or until thickened.
*Apple juice may be substituted.