In making Soupe a l’oignon Gratinée, or French Onion Soup, there are two basic schools of thought: 1) the Paris school, which developed around the wholesale market at Les Halles, and which always features beef broth 2) the Lyon school, which demands a soup made with chicken stock, maybe because of the proximity to Lyon of Bresse and its famous rouge-blanc-bleu chickens. I prefer the Lyonnais style, because the use of lighter flavored chicken stock allows the taste of the onions to be featured.
At Le Pichet and Cafe Presse, we add “duck jello” to our onions soup. Duck jello is the term we use to refer to the gelatin rich duck juices that are left in the bottom of the pot when slow cooking duck legs for confit. Clearly this is an ingredient that is not in every larder. This sort of addition is typical of the French bistro kitchen, where nothing tasty is ever allowed to go to waste.
For 8 Servings: