Ingredients:

3 tablespoons vegetable oil
6 medium white onions, sliced
8 cups beef broth (Swanson is best)
1 cup water
2 1/2 teaspoons salt
1/2 teaspoon garlic powder
1/4 teaspoon ground black pepper
5 plain hamburger buns
10 slices provolone cheese
10 teaspoons shredded parmesan cheese

Direction to cook:

step1 First take 3 tablespoons oil in a large soup pot or saucepan over medium/high heat. 
step2 Now add the sliced onions and sauté for 20 minutes until the onions begin to soften and start to become translucent.
step3 Add the beef broth, water, salt, garlic powder and black pepper to the pan and bring mixture to a boil. When soup begins to boil, reduce heat and simmer for 45 minutes.
step4 To make the croutons, cut off the top half of each top of the hamburger bun so that the bread is the same thickness as the bottom half of each bun. 
step5 Now take 10 round pieces of bread 5 bottom buns, and 5top buns with the tops cut off. Preheat in oven to 325 degrees.
step6 Place the bread in the the oven directly on the rack and bake for 15 to 20 minutes or until each piece is golden brown and crispy. Set these croutons aside until you need them.
step7 When the soup is done, spoon about 1 cup into an oven-safe bowl. 
step8 Float a crouton on top of the soup, then place a slice of provolone cheese on top of the crouton. Sprinkle 1/2 teaspoon of shredded parmesan cheese over the provolone.
step9 Place the bowl into your oven set to high broil.  
step10 Broil the soup for 5 to 6 minutes or until the cheese is melted and starting to brown. 
step11 Sprinkle an additional 1/2 teaspoon of shredded parmesan cheese over the top of the soup and serve.