Bountiful Black Bean Soup
["1 lb. dried black beans, rinsed and picked over", "4 qt. chicken broth (homemade or canned)", "1 bunch celery with leaves, chopped", "1 lb. carrots, chopped", "2 large onions, chopped", "grated zest of 1 large lemon", "1/4 c. fresh lemon juice", "1 tsp. salt", "1/4 tsp. freshly ground black pepper", "1 large lemon, thinly sliced and then slices quartered"]
["In large saucepan, combine beans with enough water to cover by 1-inch. Bring to boil over high heat. Boil 1 minute. Remove pan from heat. Cover tightly and let stand 1 hour (or soak beans overnight in large bowl with enough cold water to cover by 1-inch). Drain beans."]
["black beans", "chicken broth", "celery", "carrots", "onions", "lemon", "lemon juice", "salt", "freshly ground black pepper", "lemon"]