Method

Melt the butter in a soup pot over medium-high heat.
Add the onions and garlic and cook until tender and brown about 25 minutes. Stir occasionally.
Add the chicken and beef stock and reduce the heat to medium-low.
Add bay leaves, parsley, salt & pepper. Simmer for about 20 minutes and taste for seasoning adjustments.
Ladle soup into oven proof bowls and top each with a slice of crusty toasted French bread and generously sprinkle with the grated cheeses.
Put the bowls under the broiler until cheeses melt and bubble.