This is an original recipe by Thomas Keller posted on GastroChick.com. This soup is so amazing I could never take credit for it. So many recipes for French Onion soup skimp on the time to caramelize the onions, but the lengthy caramelization is what provides that amazing depth in a loving, patiently prepared, French Onion Soup. I hope you enjoy this as much as I have.
Note from GastroChick:
Keep an eye on your onions when cooking, if you notice there is too much liquid in the pan turn up the heat and make sure you dry them out a little otherwise they will boil instead of caramelize.