1 cup tuna in water
3 tbsp low-fat mayonnaise
1 tbsp mustard
1/4 cup celery, chopped
1/2 apple, sliced
1/2 cup romaine, chopped
1 tomato, sliced
1 slice low-fat cheese
1 slice whole-wheat bread or wrap, toasted

Take tuna and stir in mayonannaise, mustard, celery, apple and walnuts. Put on bread and top with low-fat cheese, romaine and sliced tomato.