5 tablespoons unsalted butter
1-1/2 pounds yellow onions, peeled and thinly sliced
1/2 pound shallots, peeled and thinly sliced
3 tablespoons unbleached all-purpose flour
6 cups beef or vegetable stock
1/2 cup ruby port
1/4 cup cognac, or to taste
4 bay leaves
6 to 8 sprigs fresh or 2 teaspoons dried thyme
10 whole black peppercorns, lightly crushed
1 carrot, left whole
Salt to taste
Toasts:
8 slices French bread, each 1/2-inch thick
1/2 pound Gruyere or other good-quality Swiss-type cheese, grated or thinly sliced
To make soup, melt butter in large, heavy-bottomed pot over medium heat. Add onions and shallots and sauté about 20 minutes, or until soft and caramelized. Sprinkle flour over onions, stir and cook a few minutes longer. Pour in stock, port and cognac and add bay leaves, thyme, peppercorns and carrot. Bring to boil, reduce heat to low and simmer, uncovered, about 45 minutes, or until slightly thickened and caramel in color. Remove carrot, bay leaves and thyme sprigs and discard. Add salt. To make toasts, heat broiler or oven to 400 degrees. Arrange bread slices on baking sheet and top with cheese. Toast until cheese is melted and bread is very lightly browned. To serve, place a slice of toast in a soup bowl and top with soup.