2-3 tbsp Olive oil
4-5 Yellow onion, peeled and soaked in cold water overnight for at least 4 hours
1/2 bottle Sherry wine
5 cans Beef broth
1 large can Chicken broth
Salt & pepper, to taste
Toasted croutons or toasted french bread rounds
1-2 cups Gruyere or swiss cheese, grated
Remove onions from water and cut onions into julienne slices. Set aside. In a large stock pot, heat oil on medium heat and add onions. Stir once and let it cook 10 - 15 minutes. Stir again and finish cooking until onions are tender and somewhat carmel brown, but not burnt on the bottom.
Add in the sherry wine and increase the temperature to medium-high heat and reduce until the liquid is almost, but not completely gone. Add in the rest of the remaining liquids, bring to a boil, reduce heat and let simmer for 30 - 40 minutes. Taste the liquid and add salt and fresh pepper to taste.
Place hot soup in oven tempered soup crocks and top with croutons and cheese. Bake in oven until cheese is melted and brown. Serve and enjoy!