Heat broiler. Melt butter in 5-quart saucepan over medium-high heat. Add onions; stir to coat with butter. Cover; cook 8 minutes, stirring occasionally. Add sugar; cook, uncovered, stirring onions until slightly golden, about 6 minutes. Add flour; cook 1 minute longer. Stir in beef broth, 1 broth can of water and the red wine. Simmer, covered, 5 minutes.