1Toss onions, butter and sugar in 5- to 6-quart slow cooker. Top with bay leaves and beef.
2Cover and cook on low heat setting 9 to 10 hours or until onions are deep brown.
3Stir in beef consommé, sherry, apple juice and thyme. Increase heat setting to high. Cover and cook 10 minutes or until hot. Remove bay leaves.
4To serve, spoon into ovenproof soup bowls and top each serving with slice of toast and 1/4 cup cheese. If desired, broil with tops 6 inches from heat 3 to 5 minutes or until cheese is bubbly and begins to brown.