Chicken Curry Salad

3 C cooked chicken breast, cut in bite-sized pieces
1 can (15-3/4 oz) unsweetened pineapple chunks, drained
1 C sliced celery
2 T unsalted dry-roasted peanuts
2 T reduced-fat mayonnaise
2 T plain nonfat yogurt
1/2 tsp curry powder
1-1/2 C green seedless grapes

Mix chicken, pineapple, celery, and peanuts. Combine mayonnaise, yogurt, and curry powder; pour over chicken and toss gently. Fold in grapes. Serve on lettuce leaves.