1. In 4-quart saucepan, melt butter over medium heat and cook onions, stirring frequently, 20 minutes or until onions are golden brown.
2. Stir in Lawry's® Au Jus Gravy Mix and water. Bring to a boil over high heat. Reduce heat to low and simmer covered, stirring occasionally, 10 minutes. Serve, if desired, with croutons topped with melted Gruyere cheese.