3 tablespoons nonfat plain yogurt
3 tablespoons mayonnaise
2 tablespoons finely chopped red onion
2 tablespoons white-wine vinegar
1/4 teaspoon white pepper
1/8 teaspoon salt
8 hard-boiled eggs
1 5- to 6-ounce can chunk-light tuna in water, drained
1 cup chopped cooked green beans
3 tablespoons chopped Kalamata olives
Combine yogurt, mayonnaise, onion, vinegar, pepper and salt in a medium bowl.
Halve the eggs and gently mash in a bowl. Add the eggs to the yogurt-mayonnaise mixture. Gently stir in tuna, green beans and olives.
Place lettuce leaves on four plates. Put a generous scoop of egg salad onto each lettuce leaf.