Tuna Waldorf Salad Sandwiches

Ingredients

• 1 can (5 oz.) tuna, drained and flaked
• 1 small red delicious apple, cored and chopped
• 1/2 cup chopped celery
• 1/4 cup Hellmann's® or Best Foods® Light Mayonnaise
• 1/4 cup chopped toasted walnuts
• 2 Tbsp. finely chopped onion
• 8 slices white bread or whole wheat bread
• 4 small leaves green leaf lettuce