Makes about 4 cups
Combine the grapes, apple and string cheese in a large bowl.
Whisk together the mayonnaise, tahini, toasted sesame seeds, and lemon juice in a small bowl.
Fold the dressing into the fruit and cheese salad and toss gently to coat. Taste to correct seasonings. Refrigerate, covered, to chill.
Just before serving, add 6 tablespoons of the pine nuts and toss again. Line the pitas with arugula and fill with the fruit and cheese salad. Sprinkle with the remaining toasted pine nuts.
*To toast sesame seeds and pine nuts:
Preheat oven to 350 F. Spread the seeds on a shallow baking tray and bake, shaking frequently, until fragrant and light golden, about 8 minutes.
In place of the grapes and apple, substitute equal amounts of any of the following fruits or use a combination of several - pineapple, pears, fresh or dry figs, papayas, mangoes, and peaches.