Yeah, you read that right - 4 hours. What was I thinking?
Start with 3 tablespoons of butter in an oven-proof pot and then add in 6 yellow onions cut in 1/4 inch slices (pole to pole) along with a teaspoon of salt.
Cover and cook in a 400 degree oven for an hour.
Take out of oven and give everything a good stir, scraping the sides of the pot. Then put back in oven with the lid slightly ajar for another hour and a half. Your house smells amazing at this point.
The onions are soft and golden brown.
Put the pot on the stove with a medium-high heat and cook (stirring frequently) until the liquid has evaporated.
At this point things go pretty quickly. Start de-glazing the pan with 1/4 cup of water and cook until it evaporates. Do this 2-3 times until the onions become very dark and mushy.
At this point you have a big pile of onion goo.
Add 1/2 cup of sherry or white wine and de-glaze one last time, scraping the bottom and sides of your pot.
Add in 6 cups of beef broth, 2 cups of water, a little thyme and a bay leaf and bring to just under a boil. Then reduce your heat and simmer for 30 minutes. You're almost finished at this point, I promise!
Finish it off with toasted french bread and a whole lot of cheese (I used Swiss) and put under the broiler for a few minutes until cheese melts and voila