4 tbsp. butter
1 tbsp. sugar
2 tbsp. Worcestershire sauce
Additional butter
1 c. shredded Swiss cheese
4 lg. sweet onions, sliced
6 c. beef broth, divided
4 thick slices French bread
1 garlic clove, halved

In a Dutch oven, melt butter over medium heat. Saute onions until tender. Sprinkle sugar over onions. Reduce heat and cook, stirring occasionally until onions are caramelized, about 20 minutes. Add 3 cups broth; simmer 15 minutes. Add remaining broth, Worcestershire sauce and simmer for 30 minutes.

Meanwhile, spread both sides of bread with butter and rub with cut garlic. Broil bread on both sides until lightly browned. Ladle soup into oven-proof bowls. Float a slice of bread in each bowl and sprinkle with cheese. Broil until cheese is melted and bubbly.