Soup on Sunday: Hot and Sour Pumpkin Soup

This soup was inspired by the beautiful illustration by Laura de Búrca and my desire to cook with pumpkins this month.

1 large onion, coarsely chopped
1 tablespoon chopped garlic
2 tablespoon chopped peeled fresh ginger
3 tablespoons vegetable oil
1 (3-lb) sugar pumpkin, peeled, seeded, and cubed (6 cups)
1 cup dry white wine
2 qt vegetable stock
6 lemongrass stalks (bottom 5 inches only), coarsely chopped
3 to 5 fresh (1 1/2-inch) Thai coarsely chopped and
4 kaffir lime leaves (fresh or frozen)
1/3 cup fresh lime juice
1/4 cup Asian fish sauce
1 tablespoon sugar

Cook onion, garlic, and ginger in 1 tablespoon oil in a heavy pot over moderate heat, covered, stirring occasionally, until onion is softened, about 4 minutes. Add pumpkin and wine and boil, uncovered, until wine is reduced by about half, about 5 minutes. Stir in stock and simmer, covered, until pumpkin is tender, about 20 minutes.

Heat remaining tablespoon oil in a 10-inch heavy skillet over moderately high heat until hot but not smoking, then sauté lemongrass, and chiles, stirring, until lightly browned, about 1 minute. Remove from heat.

Purée pumpkin mixture in batches and return to pot. Stir in lemongrass mixture, lime leaves, lime juice, fish sauce, and sugar. Simmer, uncovered, 20 minutes. Pour soup through a sieve, discarding solids, and season well with salt and pepper.

Serves 4 - 6