Refrigerator Pasta Salad

Ingredients

• 1/4 pound cooked spaghetti, cut into 2 inch long pieces
• 1 rib celery cut into 1/4-inch dice
• 1 scallion, cut into thin rounds
• Small McIntosh apple, unpeeled, cored, and cut into 1/4-inch dice
• 1/4 cup walnuts, roughly chopped
• 6 ounces smoked chicken breast, skinned and cut into pieces, 1/4 inch wide and 2-inches long
• 2 to 3 tablespoons fresh lemon juice
• 1 teaspoon dried tarragon
• 3 tablespoons mayonnaise, regular or low fat
• 2 to 3 tablespoons sour cream, regular or low fat
• Washed Boston or Bibb lettuce leaves