Chicken Salad
["4 (4 oz.) skinned, boned chicken breast halves", "1 medium onion, halved", "1 stalk celery, halved", "1 bay leaf", "1 egg white", "1 tsp. chopped fresh tarragon", "1/4 tsp. salt", "1/8 tsp. garlic powder", "1/8 tsp. white pepper", "1 tsp. lemon juice", "2 tsp. olive oil", "2 tsp. plain yogurt"]
["Combine chicken, onion, celery and bay leaf in Dutch oven. Add water and cover.", "Simmer 15 minutes after boiling.", "Remove chicken and chop in bite-size pieces.", "Set aside.", "Discard vegetables and water.", "Combine egg white, tarragon, salt, garlic, pepper and lemon juice in blender.", "Gradually add oil just until blended; fold in yogurt.", "Pour over chicken.", "Let set 4 hours. Serve on shredded lettuce.", "Garnish with tomato and cucumber slices."]
["onion", "celery", "bay leaf", "egg", "tarragon", "salt", "garlic powder", "white pepper", "lemon juice", "olive oil", "plain yogurt"]