2 1/2 pounds yellow onions, halved, and sliced 1/4-inch thick (8 cups)
1/4 pound unsalted butter
1 bay leaf
1/2 cup medium-dry sherry
1/2 cup brandy or Cognac
1 1/2 cups good dry white wine
4 cups beef stock
4 cups veal stock
1 tablespoon kosher salt
1/2 teaspoon freshly ground white pepper
Freshly grated Parmesan

In a large stockpot on medium-high heat, saute the onions with the butter and
bay leaf for 20 minutes, until the onions turn a rich golden brown color. Deglaze the pan
with the sherry and brandy and simmer uncovered for 5 minutes. Add the white wine and
simmer uncovered for 15 more minutes.
 
Add the beef and veal stocks plus salt and pepper. Bring to a boil, then simmer uncovered
for 20 minutes. Remove the bay leaf, taste for salt and pepper, and serve hot with grated
Parmesan.