Melt butter in a large saucepan over low heat and add onions, garlic and salt. Let the onions sweat down until golden and creamy, around 20 mins or so. Add white wine and bouquet garni (or herbs), turn the heat up and reduce the wine down until syrupy. Add the chicken and beef broth, the splash of cognac and Worchestershire, S & P to taste, and turn down to simmer for 5 minutes. Turn on the oven to bake at 350°degrees F, and prepare two big (ovenproof) ceramic bowls on a cookie sheet. Remove the bouquet garni (or just the bay leaf if you’ve used fresh herbs) and slice off four pieces of French bread. Spread the bread with butter (optional), and place in the bottom of the bowls. Pour soup over the bread, cover liberally with the cheese, and place in the oven for 15 minutes until you have achieved a bubbly, melty crust. Serve with a light mésclun salad and either a decent Cotes du Rhone or a nice dark beer.