How to Make It
Melt butter in a medium saucepan over medium heat; add onion, and sauté 5 to 7 minutes or until lightly browned. Whisk in flour. Cook, whisking constantly, until lightly browned (about 1 minute). Gradually whisk in broth and next 2 ingredients. Cook, whisking constantly, until thickened and bubbly. Garnish, if desired.