We only serve this sweet, creamy soup during the autumn and winter months. Perhaps because of its limited season, it has developed somewhat of a cult following. Its personality comes from the caramelized onions floating in each spoonful. When I make this soup, I always make extra caramelized onions because they make a great topping for whipped potatoes at another meal. The onions can cook while you are preparing the rest of the soup. The soup makes an elegant first course for a fancy meal. I also used to make a batch for the annual Teacher Appreciation Day luncheon at my daughter’s school. I think they gave it an A, because every time I walked into the school, I was greeted with many smiles.

Ingredients:

Caramelized Onions-
2 tablespoons salted butter
2 large Spanish onions, peeled and thinly sliced
1/2 cup packed dark brown sugar
Kosher salt and freshly ground black pepper, to taste
1/4 cup balsamic vinegar
Soup-
4 tablespoons salted butter
3 whole cloves garlic, peeled and left whole
2 cups sliced onions
2 cups sliced carrots
1/4 cup diced celery
8 medium-large sweet potatoes, peeled and cut into chunks
10 cups chicken stock
1/2 cup packed brown sugar
1/2 teaspoon ground nutmeg
2 tablespoons Worcestershire sauce
2 cups light cream
1/2 cup sweet sherry wine
Kosher salt and freshly ground black pepper, to taste
1^1/2 cups caramelized onions

Directions:

For the caramelized onions: In a large sauté pan melt the butter over medium heat. Add the onions and sauté for 18 minutes. Add the brown sugar, salt and pepper. Sauté an additional 10 minutes. Add the vinegar and continue cooking until the vinegar starts to evaporate and the onions look thick and syrupy, 8 to 10 minutes more. Remove from the heat and let cool. If working ahead, the onions can be stored in a tightly covered container until ready to use.

For the soup: In a stockpot melt the butter over medium-high heat. Add the garlic, onions, carrots, and celery. Sauté for 10 minutes. Add the sweet potatoes and sauté 5 minutes more. Pour the stock over the vegetables and bring to a boil. Reduce the heat to medium and simmer until the sweet potatoes are very soft, 30 to 35 minutes. Puree the soup in the pot using a hand blender or working in batches with a regular blender until smooth. Add the brown sugar, nutmeg, Worcestershire sauce, light cream, sherry, salt, and pepper. Puree again until well combined. Stir the caramelized onions into the soup with a spoon.

Makes 8 to 10 servings. If you recognize caramel from candy, the technique of caramelizing is related. In candy, sugar is cooked until it liquefies and browns. In this recipe the onions are cooked with sugar and balsamic vinegar in a large sauté pan. All the sugars, including those that occur naturally in the onions and the vinegar, cook down and become syrupy.