This soup is the perfect comfort food for a cold winter day. It's also a great way to use up leftover beef broth and crusty bread. The soup is relatively easy to make, but it does take some time to cook the onions. If you're short on time, you can always use pre-sliced onions or even frozen onions.
Once the onions are cooked, the soup is simply a matter of adding the remaining ingredients and simmering it for a few minutes. You can adjust the amount of Worcestershire sauce and pepper to your taste. And if you don't have any sherry on hand, you can substitute white wine or even chicken broth.