Avgolemono Soup with Asparagus and Dill

3 pounds asparagus
4 cups vegetable stock
Salt
2 tablespoons olive oil
3 medium leeks, white part, washed well and sliced crosswise
3 ribs celery, thinly sliced
Freshly ground pepper
2 cups water
3 large eggs
Juice of 2 lemons
1/4 cup minced fresh dill
additional fresh dill sprigs for garnish

Trim ends of asparagus. Using a vegetable peeler, remove 3 to 4 inches of the skin of each stalk, reserving both the ends and peels. Cut asparagus into 1-inch pieces, reserving tips for garnish. In a saucepan, combine the asparagus peels and trimmings with the vegetable stock; bring to a boil, remove from heat and allow stock to infuse for 15 minutes. Strain stock and reserve. In a pot of salted boiling water, blanch the asparagus tips for 2 to 3 minutes or until brilliant green and barely tender; refresh in a bowl of ice water. When tips are chilled, drain and reserve.

In a large heavy pot, heat the olive oil over moderate heat. Add the leeks and celery, seasoned with salt and pepper to taste, and cook until softened, about 5 to 8 minutes. Add the 1-inch asparagus pieces and stir to combine. Add the infused stock and water, bring to a boil and simmer, covered, for 8 to 10 minutes, until asparagus is tender.

In a blender, puree the soup, in batches, until smooth. Return pureed soup to large pot and let cool to lukewarm.

In a heatproof bowl, whisk together eggs and approximately 1/4 cup lemon juice (reserve remainder), adding 1 cup of the lukewarm soup in a stream, while whisking constantly. Whisk the egg mixture into the remaining soup. Cook the soup over moderately low heat without boiling, whisking constantly, until thickened slightly and temperature of soup reaches 160 degrees on a candy thermometer.

Whisk in minced dill, remaining lemon juice, and salt and pepper to taste. Serve soup hot or chilled, garnished with the asparagus tips and dill sprigs.

Yield: 6 to 8 servings.

Source: Adapted from "Savor a Springtime of Fresh Vegetables"