1/2 cup walnuts halves
1/2 cup non-fat yogurt
2 tablespoons light mayonnaise
2 tablespoons minced fresh flat-leaf parsley
1 teaspoon honey
1/2 lemon, zest finely grated
Freshly ground black pepper
2 large crisp apples, such as Gala
2 ribs celery (with leaves), sliced into 1/2-inch-thick pieces (leaves chopped)
1/4 cup golden raisins
1/2 lemon, juiced
1 head Boston lettuce, trimmed, washed, and dried