Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
1         large         apple -- cored and diced
1         can           pineapple chunks -- 11oz,drained
1         1/2           cups sliced celery
3         cups          cooked rice
2         cans          tuna in water -- 6oz,drained
3/4       cup           plain yogurt
1         tablespoon    soy sauce
1         tablespoon    lemon juice
1         tablespoon    sesame seeds
1         head          Boston lettuce -- washed and dried

Preparation:

In a large mixing bowl combine apple, pineapple, celery, rice and tuna. In a small bowl whisk together yogurt, soy sauce and lemon juice. Pour dressing over tuna mixture and toss lightly. Chill. Put sesame seeds in a heavy skillet; toast them over medium heat until they are golden, shaking the pan to avoid burning. Remove seeds from pan and let cool. Arrange lettuce leaves on plates, equally divide tuna mixture among them and sprinkle with toasted sesame seeds.