French Onion Soup is one of the great comfort dishes of all time. But, add in the Gratinee and it is the ULTIMATE comfort dish of all time. Seriously, what's better than soup covered in toasted bread and tons of cheese? The only thing that may make this dish unapproachable is the large amount of onion slicing you'll have to do. Go buy goggles or something and suck it up. I have the worst problem with onions. My eyes turn red and puffy and I cry like my best friend just died. If I can get through it, you can get through it, I promise. Some people may look at the amount of onions I'm putting in and think, "Woa! That's a lot of onions!" Well, the thing is that onions have so much liquid in them that as you continue to cook them, the liquid exudes and evaporates, and you'll end up with maybe 1/4 of the onions you started with.
10 Cups sliced yellow onions - yes, 10 Cups
*10 Cups is a little more than 2 Quarts. An easy way to measure is to grab a 2 Quart mixing bowl and just keep adding the sliced onions until it's a heaping mass, rather than measuring cup by cup.
3 Tbsp. unsalted butter
2 Tbsp. canola oil
1 tsp. salt
1 tsp. sugar
2 Tbsp. all-purpose flour
10 Cups beef broth (2 Quarts and 2 Cups)
1 Cup extra dry French vermouth
Freshly ground black pepper
1 16-inch Baguette loaf, sliced 1/4 inch thin
8-16 Ounces of grated cheese, depending on how much you like - I use Gruyere, but Swiss is a good choice
Heat a large stockpot over medium-low heat. Add the butter and oil, onions, and salt. Cover and cook for about 20 minutes, or until softened. Stir in the sugar and saute an additional 15 minutes over medium heat, stirring occasionally, until golden brown.
Meanwhile, in a separate pan, heat the stock until just simmering.
Preheat the oven to 350 degrees.
Sprinkle the flour over the onions and stir. Cook for about 1-2 minutes, just to get rid of the raw flour taste. Whisk in about 3-4 ladle-fulls of the hot stock in order to incorporate the flour into the liquid. When the flour is well blended, add the rest of the stock and the extra dry French vermouth. Simmer, covered slightly, for about 25-30 minutes. Season with any additional salt, the nutmeg, and the pepper.
While the soup is simmering, lay the bread slices onto a sheet pan and toast for 25 minutes, or until lightly browned and crisp.
Re-preheat the oven to 450 degrees.
Line the bread slices into the bottom of a large casserole dish OR in individual crocks, I like to add some grated cheese to the bottom of the dish as well. Ladle in the soup. Float the remaining toast slices on the top, covering the entire dish. Generously cover the top with the grated cheese. Very carefully transfer the casserole to the oven and bake for about 20 minutes, or until the cheese is melted and browned.