Babsi's broccoli soup

2 cups    chopped broccoli (stems and florets)    500 mL 2 cups    chicken broth    500 mL 1 cup    buttermilk    250 mL 1/2 tsp    dried basil    2 mL 1/2 tsp    dried tarragon    2 mL      salt and black pepper to taste, small broccoli florets, lower fat plain yogurt, chives, shredded cheddar cheese     In a saucepan over medium-high heat, cook broccoli in chicken broth for 10 minutes or until tender. Refrigerate in broth until chilled. In a food processor or blender, purée chilled mixture, buttermilk and seasonings until smooth. Taste and adjust seasonings. Reheat just to serving temperature, or chill and serve as cold soup. Serve garnished with broccoli, yogurt, chives and Cheddar cheese.