In a mixing bowl, whisk together mayonnaise, sour cream, lemon juice and sugar. Stir in chopped herbs.
Using a vegetable peeler, peel stringy outer layer from celery, and diagonally into thin slices to make about 2 cups. Turn into mixing bowl.
Remove core and cut apple into 1/8-inch slices, and then into matchsticks. Add to bowl along with walnuts and raisins. Spoon in dressing and toss to coat ingredients well. Season to taste with salt and pepper. Chill for at least 1 hour before serving.
Arrange 1 large radicchio or butter lettuce leaf on each of 8 salad plates or bowls. Divide and spoon salad on top. Sprinkle on a few more raisins and/or walnuts to garnish the salad, if desired, and serve.
- 1 Cup mayonnaise
- 1/4 Cup sour cream
- 1 Teaspoon lemon juice
- 2 Teaspoons granulated sugar
- 1/4 Cup chopped Italian parsley
- 1 Tablespoon chopped basil
- 1 Teaspoon chopped dill
- 4 large ribs celery
- 1 large Granny Smith apple
- 1 Cup toasted walnuts
- 1 Cup California raisins
- Kosher or sea salt and freshly ground pepper
- 4 large radicchio or butter lettuce leaves