SOUP: 3 tablespoons unsalted butter

1 (10-oz) russet potato, peeled and cut in -- 1/4

inch dices 1 (10-oz) firm-ripe pear, peeled, cored, -- chopped

1 large onion, -- chopped

4 cups chicken broth

1 teaspoon fresh thyme leaves, chopped or 1/2 tsp -- dried

1 package (10-oz) frozen peas

1 bunch watercress, rinsed, coarse stems discarded

8 sprigs watercress for garnish

1 teaspoon salt

freshly ground pepper LEMON-PEPPER CREAM: 1/2 cup sour cream

2 tablespoons fresh lemon juice

1/2 teaspoon freshly ground pepper

SOUP: In 4-quart Dutch oven, melt butter. Add potato, pear and onion; cook covered, over low heat, stirring often, 20 minutes, until potato is tender. Add chicken broth and thyme; bring to a boil. Reduce heat to low, cover; simmer 8 minutes. Add peas and watercress; bring to boil. Reduce heat; simmer 3 minutes. In blender, puree in batches. Add salt and pepper. LEMON-PEPPER CREAM; Whisk together ingredients. To serve: Ladle 1 cup soup into each of 8 bowls. Serve hot, at room temperature or chilled. Drizzle with Lemon-Pepper Cream. Garnish with watercress.