Gratinee Lyonnaise (Lyon-Style Onion Soup) - cooking recipe

Ingredients

4 tablespoons unsalted butter or 4 tablespoons unsalted margarine
3 lbs yellow onions, thinly sliced
1 1/2 teaspoons salt
1/2 teaspoon fresh ground pepper
1/3 cup cognac
8 cups beef stock or 8 cups broth
4 sprigs fresh thyme, tied into bundle
1/2 loaf French bread, cut into 1/2-inch slices
1 lb gruyere cheese, coarsley grated
2 egg yolks (optional)
1/2 cup port wine (optional)
finely chopped parsley, garnish

Preparation

In a Dutch oven or other large pot melt the butter or margarine over med-high heat. Add the onions, salt and pepper, & cook, stirring until golden bown, 15 to 18 miutes.
Remove the pan from the heat & carefully add the cognac.
Return the pan to the heat & cook until the alcohol has evaporated. Be careful as the cognac may ignite.
Add the beef stock & thyme sprigs & bring to a boil. Reduce the heat to a simmer & cook the soup for 45 minutes.
While the soup is simmering, toast the bread slices until light golden brown. Remove from oven.
Preheat the broiler.
When the soup is ready, divide 1/2 of the toasted bread slices between 6 individual ovenproof serving bowls or crocks and top with 1/2 of the grated cheese.
Ladle some of the soup among the bowls and top with the remaining toasts. Ladle the remaining soup among the bowls and top with the remaining cheese.
Place the bowls on baking sheet and place under the broiler until the cheese is melted, golden brown and bubbly, about 5 minutes.
Remove from the oven.
Optional Topping: In a small bowl combine egg yolks and Port and whisk to thoroughly combine. Pour some of the mixture evenly among the soup bowls, stirring in aroud the edges so that it is incorporate into the soup. (The heat of the soup will cook the egg yolk and this will thicken & enrich the soup.).
Garnish the top with chopped parsley and serve hot.