Ranch Chicken Salad Sandwiches

Ingredients

• 1/4 cup reduced-fat mayonnaise
• 3 tablespoons fat-free ranch salad dressing
• 3 tablespoons fat-free sour cream
• 1 tablespoon lemon juice
• 1/8 teaspoon pepper
• 2 cups cubed cooked chicken breast
• 1/2 cup thinly sliced celery
• 2 tablespoons diced sweet red pepper
• 1 tablespoon chopped green onion
• 6 hamburger buns, split
• 6 lettuce leaves
• 6 slices tomato