6 onions, peeled and thinly sliced.
Olive oil
1/4 teaspoon of sugar
2 cloves garlic, minced
8 cups of beef stock or chicken stock
1 bay leaf
1/4 teaspoon of dry thyme
Salt and pepper
8 slices of toasted French bread
1 1/2 cups of grated mozzarella
The deep flavor of French onion soup comes from caramelizing the onions. You have to have patience with this step; you can't skip it or speed it up. In a large pot, heat a good amount of olive oil over medium-high heat then add the onions. It will take approximately 30 minutes to get the onions a nice deep brown color. Keep stirring them occasionally, don't let them burn. Add the sugar about 10 minutes into the process to help with the browning.
Once the onions are soft and a deep caramel color, add the garlic and saute for about a minute. Then add the stock, bay leaf and thyme. Turn the heat down to a simmer and put a lid on the pot so it is partially covered. Simmer for about 30 minutes. You'll notice the longer you simmer, the flavors become more developed and the color of the soup with deepen. Season to taste with salt and pepper and throw out the bay leaf.
When you are ready to eat, heat your oven to broil. Ladle the soup into oven-proof bowls, top with a piece of toasted bread and sprinkle with a good amount of cheese. Put into broiler until the cheese is nice and golden brown.