The best French Onion Soup I've had outside of France! A deep broth flavor enhanced by wine, cognac and caramelizing of onions.
Over medium heat, melt 2 Tablespoons of butter and 1 Tablespoon of olive oil in a wide bottom heavy pot. When the butter has melted, add the onions and stir to coat with the butter & olive oil. Cook the onions, stirring occasionally, until tender and translucent, about 20 minutes depending on the quantity of onions and how wide your pot is.
Add salt, pepper, sugar, oregano and Worcestershire sauce and stir to combine well. Allow the onions caramelize about 15 minutes or until they reach an even and deep golden walnut color.
Note: a wooden spoon works best to scrape the pot.
In a sauce pan, heat 2 cups of beef stock.
Make a well in the center of the pot and add 1 Tablespoon of butter. Sprinkle in the flour and cook an additional 3-4 minutes scraping the bottom and stirring constantly. Add 2 cups of hot beef stock and stir constantly to blend well, without lumps.
Add the remaining stock, Cognac, wine, fresh thyme and bay leaf. Cover and simmer for an hour. Taste and reseason, if needed.
Note: If your stock reduced too much, add a little extra stock or water.
Set the oven rack slightly above the midpoint and set the oven temperature to broil.
Divide the soup among your ovenproof bowls. Arrange the French bread on top of the soup and generously top with Gruyere cheese.
Transfer bowls to a cookie sheet and broil in the oven until the cheese melts and begins to brown. Remove from the oven and rest for 5 minutes. Garnish with fresh thyme sprig.
Note: Do not walk away from the oven when broiling. Your dish can quickly burn.
This recipe uses salted beef stock. If you are using unsalted beef stock, increase the amount of salt.