We love this soup, we have made it before á la Julia Child. It was one of the first thing I made from her classic book.
David uses chicken stock not beef stock and it is just as good. I did not follow his recipe to the letter. I did not use balsamic vinegar. I used cognac. It takes such a long time to caramelize the onion that I did not take any chances. I know I love cognac. The last time I made this soup from Julia’s book I only had some crappy sugar and it burnt I almost cried. It ruined everything. This time around the onion was a bit on the light side, I was so stressed it would burn so I kept the heat too low. Well live and learn.