My Version of French Onion Soup

I took what I thought was the best of a couple of recipes and it became this:

4 lbs yellow onions
6 cloves garlic
1 tsp salt
3 tbls unsalted butter cut into 3 pieces
¾ cup wine (whatever you have - red or white)
⅓ cup cognac

2 cans chicken broth

2 cans beef broth

6 sprigs fresh thyme tied with kitchen twine

1 bay leaf

1 tsp Dijon mustard

Sourdough bread

Gruyere or Swiss cheese, grated or shaved

Directions:
For the soup:

1. Adjust the oven rack to the lower-middle position and heat the oven to 350 degrees.
2. Generously spray the inside of a heavy-bottomed large (at least 7-quart) Dutch oven with a nonstick cooking spray. Place the butter in the pot and add the onions and 1 teaspoon salt. Cook, covered, for 1 hour (the onions will be moist and slightly reduced in volume). Remove the pot from the oven and stir the onions, scraping the bottom and sides of the pot. Return the pot to the oven with the lid slightly ajar and continue to cook until the onions are very soft and golden brown, 1 1/2 to 1 3/4 hours longer, stirring the onions and scraping bottom and sides of pot after 1 hour.
3. Carefully remove pot from oven and place over medium-high heat. Using oven mitts to handle pot, cook onions, stirring frequently and scraping bottom and sides of pot, until the liquid evaporates and the onions brown, 15 to 20 minutes, reducing the heat to medium if the onions are browning too quickly. Continue to cook, stirring frequently, until the pot bottom is coated with a dark crust, roughly 6 to 8 minutes, adjusting the heat as necessary. (Scrape any fond that collects on spoon back into onions.)
4. Stir in 1/4 cup wine, scraping the pot bottom to loosen crust, and cook until water evaporates and pot bottom has formed another dark crust, 6 to 8 minutes. Repeat process of deglazing 2 or 3 more times, until onions are very dark brown. Stir in the cognac and cook, stirring frequently, until the cognac evaporates, about 5 minutes.
5. Stir in the broths, mustard, thyme, bay leaf, and ½teaspoon salt, scraping up any final bits of browned crust on bottom and sides of pot.
6. Increase heat to high and bring to simmer. Reduce the heat to low, cover, and simmer for 30 minutes. Remove and discard herbs, then season with salt and pepper.

While the soup is cooking slice the bread and put on baking sheet in 400 degree oven for abaout 10 minutes until the bread is dry, crisp, and golden at edges.

Adjust oven rack 6 inches from broiler element and heat broiler. Set individual broiler-safe crocks on baking sheet and fill each with about 1¾cups soup. Top each bowl with 1 or 2 bread slices (do not overlap) and cover evenly with cheese. Broil until cheese is melted and bubbly around edges, 3 to 5 minutes. Let cool 5 minutes before serving.

Let soup cool sufficiently to be able to taste the flavor. If eaten when it is too hot the savory flavor is lost.