Pumpkin, Corn, and Lemongrass Soup

Directions

1. 1.

   Cut off and discard top of lemongrass, leaving a 6-inch stalk, then smash stalk with side of a large heavy knife.

2. 2.

   Cook lemongrass, onion, and 1 teaspoon salt in butter and oil in a heavy medium pot over medium-low heat, stirring occasionally, until onion is softened, about 10 minutes. Add squash, corn, water, 1 1/2 teaspoons salt, and 1/2 teaspoon pepper and bring to a boil over high heat.

3. 3.

   Reduce heat and simmer, covered, stirring occasionally, until squash is tender, about 10 minutes. Remove from heat and discard lemongrass.

4. 4.

   Purée soup in 3 or 4 batches in a blender until very smooth (use caution when blending hot liquids), straining each batch as blended through a fine-mesh sieve into a large heatproof bowl, pressing hard on and then discarding solids. Season with salt and pepper and reheat if necessary.