The secret to a rich French onion soup is caramelized onions. By taking the time to caramelize the onions you will be rewarded with sweet rich brown flavors. This recipe uses simple ingredients that you probably have in your pantry.
Butter – 4 tbsp
Onions – 5 medium onions – slice thin about 1/4” thick
Sugar - ½ tsp
Salt ¼ tsp
Flour - 2 tbsp – or gluten free - substitute a slurry of 1 tbsp cornstarch and 1tbsp water
Beef broth – 4 cups or 1 box – vegans can substitute with vegetable broth
Bay Leaf – 2 leaves
Thyme - 2 tsp
Salt + Pepper – to taste
Sherry – ½ cup or substitute with brandy, sake or a dry white wine
French bread – about ½ baguette
Gruyere Cheese – 4 oz grated
Parmesan – 4 oz grated
Melt the butter in a heavy bottom pan, add onions. Cook on medium-low for about 25 minutes until the onions are soft and translucent. Add the sugar and salt and stir often until are golden brown and caramelized, about 15 minutes. They will be very soft and sticky. Sprinkle the flour over the caramelize onions and cook it for a couple of minutes – or add the slurry. Add sherry, Nutmeg and stock. Bring to a simmer and cook for another 30 minutes. Season with salt and pepper to taste.
Slice the bread about ½” thick, top with mixture of Parmesan and Gruyere cheese and lightly toast under the broiler then top with cheese and continue to broil until it is bubbling and melted.
Remove the bay leaves, ladle the hot soup into bowls, place the bread on top and serve.