now before you go asking if this soup is really that different from yesterday’s onion soup recipe, the answer is a definitive, “YES!”
this soup’s success depends on caramelizing the onions and leeks, a technique that takes time and patience. caramelization occurs when the sugars naturally present in a vegetable slowly develop a less purely sweet, more complex flavor through long cooking over medium-low or medium heat. adding a sprinkling of sugar encourages the caramelizing process.
- 2 tbs. vegetable or olive oil
- 4 large red onions, thinly sliced
- 1⁄4 tsp. sugar
- 4 leeks, including tender green portions, thinly sliced
- 2 garlic cloves, minced
- 8 cups mushroom or vegetable broth
- 1⁄2 cup dry white wine
- 1 bay leaf
- 1⁄2 tsp. minced fresh thyme or 1⁄4 tsp. dried thyme
- salt and freshly ground pepper, to taste
- 12 baguette slices, each 1⁄4 inch thick
- 3⁄4 cup shredded gruyère or comté cheese
in a large nonaluminum saucepan over medium-low heat, warm the oil. add the onions and sauté, stirring occasionally, until wilted, about 15 minutes. add the sugar and leeks and continue cooking, stirring frequently, until richly colored and caramelized, 30 to 45 minutes. (you may need to increase the heat to medium to add some color at the end.)
add the garlic and sauté for 1 minute. add the broth, wine, bay leaf and thyme. cover partially and simmer until the flavors are well blended, about 30 minutes. season with salt and pepper. remove the bay leaf and discard.
to serve, preheat the broiler. ladle the soup into individual flameproof soup bowls. place 2 or 3 slices of bread on top of each bowl and sprinkle with the cheese. slide under the broiler about 6 inches from the heat element. broil until the cheese is bubbly and lightly browned, 3 to 4 minutes. serve immediately. serves 4 to 6.
serving tip: serve a simple green salad with this soup for a satisfying light dinner!