Crunchy Waldorf salad with blue cheese

Ingredients (serves 4): 1/4 cup buttermilk 1 tablespoon low fat mayonnaise 1 tablespoon sour cream 1 tablespoon lemon juice 2 small pink lady apples, cut into 2.5cm cubes 2 celery stalks, halved lengthways, chopped 1/3 cup chopped walnuts, toasted 1/2 lettuce, leaves separated, torn 50g blue cheese, finely crumbled   Method: Place buttermilk, mayonnaise, sour…