ingredients that are required for this recipe :
White onions - 6 (sliced)
Beef stock - 8 cups
Water - 1 cup
Hamburger buns - 5
Parmesan cheese - 10 teaspoons
Provolone cheese - 10 slices
Salt - 2 to 3 teaspoons
Black pepper - 1/4 teaspoon
Oil - 3 tablespoons
Garlic powder - 1/2 teaspoon

Recipe:
Heat oil in large pot to medium heat. Saute the onions for 8 to 10 minutes until they're soft.

Add in beef stock, water, garlic powder, salt, and black pepper. Bring to a boil. When boiling, reduce heat and simmer (slow cooking, make it bubble or simmer) for 45 minutes.

Separate the hamburger buns top and bottom. Cut the crown off the top half, so top and bottom are same size. Then bake at 325F for about 20 minutes. These are your croutons.

When the soup is done, spoon 1 cup into an oven-safe bowl, and place a crouton on top. Lay a slice of provolone cheese on top, and sprinkle 1/2 teaspoon of parmesan cheese over the provolone.

Turn the heat of oven to broil and cook the soup for 5 minutes or so until cheese is melted, and turning golden. Spread another 1/2 teaspoon parmesan on top and serve.