Summer-Squash Soup with Parsley-Mint Pistou
Adapted from Gourmet, September 2006
For squash soup
3/4 stick (6 tablespoons) unsalted butter, cut into pieces
1 medium onion, halved lengthwise and thinly sliced crosswise
1/2 teaspoon salt
2 lb yellow summer squash, halved and thinly sliced
2 carrots, thinly sliced
1 yellow-fleshed potato (1/2 pound), peeled, halved, and thinly sliced
4 cups chicken stock or reduced-sodium chicken broth (use vegetable broth to make it vegetarian)
3/4 cup loosely packed fresh mint leaves
1/2 cup loosely packed fresh flat-leaf parsley sprigs
1 large scallion, chopped (1/2 cup)
1/4 cup extra-virgin olive oil
2 tablespoons water
1/4 teaspoon salt
Make soup: Melt butter in a 6- to 8-quart wide heavy pot over moderate heat, then cook onion with salt, stirring, until softened, about 8 minutes. Add squash, carrots, potato, and stock and bring to a boil. Reduce heat, then simmer, partially covered, until vegetables are very tender, about 20 minutes. Remove from heat and cool soup, uncovered, 10 minutes.
Working in batches, puree; soup in a blender until smooth (use caution when blending hot liquids) and transfer to a bowl. Return purée to cleaned pot and thin with water if desired; simmer 3 minutes. Season with salt.
Make pistou while vegetables simmer: Pulse mint, parsley, and scallion in a food processor until finely chopped. With motor running, add oil in a stream, then add water and salt, blending until incorporated.
Swirl 1 tablespoon pistou into each bowl of soup.