3 tablespoons unsalted butter
2 cups chopped leeks (white and pale green parts only) 1 garlic clove, chopped
1 1/2 pounds russet potatoes, peeled, cut into 1-inch pieces
4 1/2 cups (or more) canned low-salt chicken broth
1 10-ounce package frozen peas
1 cup whipping cream
Additional whipping cream
Melt butter in heavy large saucepan over medium heat. Add leeks; saute 3 minutes. Add garlic; saute 1 minute. Add potatoes and 4 1/2 cups broth; bring to boil. Reduce heat, cover and simmer until potatoes are very tender, stirring occasionally, about 15 minutes. Add peas; cover and continue cooking until just tender, about 5 minutes. Working in batches, puree soup in blender. Transfer to bowl. Cool slightly. Chill uncovered until cold, then cover and chill. (Can be made 1 day ahead. Keep chilled.) Mix 1 cup cream into soup. Thin soup with more broth, if desired. Season soup to taste with salt and pepper. Ladle soup into bowls. Drizzle with additional cream and garnish with chives.