* In a medium pot melt the butter and add all the sliced onions. Cook covered, stirring occasional to encourage caramelization.
* After the onions are a golden brown cool it down with the sherry. Simmer for 5 minutes and add your beef broth. Fill the can with water and combine it with the onions and broth (TWICE). Add the thyme bouillon and Worcestershire sauce then simmer for about 10-15 minutes.
* Ladle the soup into small crock bowls. Add the stale bread on top of the soup then the Swiss cheese on the bread. Place crocks on a baking sheet and broil for about 3-5 minutes or until the cheese has become gold and bubbly.
Serve immediately on small plates - be careful, the crocks will be hot!