Step 1

Preheat oven to 325 degrees F.

Step 2

In a large heavy bottom soup pot, heat the oil and sauté the onions over medium low heat, stirring only a few times, until they begin to brown, about 15 minutes (see note). Add the garlic and stir for 1 minute until very fragrant. Raise the heat, add the beef stock, water, salt, and pepper and bring soup to a boil, then lower heat and simmer for 45 minutes.

Step 3

While soup is cooking, slice the “crown” top off each of the hamburger buns, giving you 10 rounds of approximately the same size. Place on a cookie sheet and bake 20 minutes.

Step 4

Remove and change oven temperature to broil.

Step 5

When the soup is cooked, taste and adjust seasonings as desired. (see note)

Step 6

Ladle soup into individual soup bowls, top each with a crouton, then with a slice of Provolone and a sprinkle of Parmesan. Broil about 5 minutes until cheese is melted and beginning to become a golden brown. Sprinkle each with a bit more Parmesan and serve immediately.