CHILLED AVOCADO SOUP

Melt 1/4 cup BUTTER; blend in 1/4 cup FLOUR, 1 teaspoon SALT, few GRAINS PEPPER and 1/4 teaspoon dry MUSTARD.  Gradually add 4 cups MILK, blending until smooth.


Cook over boiling water, stirring constantly until slightly thick.  Chill.


Add 2 tablespoons minced ONION, 1/2 cup finely diced CELERY and 1 cup minced AVOCADO.


Pour into chilled bowls; garnish with chopped CHIVES.  Serves 4.