French Onion Soup

4 cups sliced onions
beef stock
1/2 cup unsalted butter
2 tablespoons olive oil
2 tablespoons dry sherry
1 teaspoon dried thyme
salt and pepper
1 loaf French bread
6 slices provolone cheese
3/4 cup diced Swiss cheese
1/4 granted Parmesan cheese

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Melt the butter on medium heat. Add olive oil and onions and continually stir until tender and translucent. Do not brown the onions. Add beef stock, sherry and thyme. Season with salt and pepper, and let it simmer for 30 minutes.
Ladle soup into individual, oven safe, serving bowls and place one slice of bread on top. Layer cheese on top of the bred; placing one slice of provolone cheese, 1/2 a slice of Swiss diced cheese and on top Parmesan cheese. Put the bowls into the oven and broil until cheese bubbles and browns slightly.