In a large salad bowl, whisk together lime juice, salt, pepper and olive oil. Set aside.
Place parsley in a food processor (or finely chop by hand) and pulse 4–5 times or until the parsley is finely chopped. Empty chopped parsley into a flour sack towel and twist to enclose. Hold the towel under running water and massage for 30 seconds to a minute. Squeeze all the liquid out of the towel, empty the washed and dried parsley into the salad bowl and thoroughly combine with the dressing.
Add the quinoa, mint, cucumbers, and green onions to the bowl. Stir to combine. Taste for seasoning, adding more olive oil, salt or lime juice as needed. Fold in tomatoes and chicken.
Cover and refrigerate until ready to serve.
Notes
Traditional Arabian tabbouleh is made with bulgur (dried cracked wheat) but we opted for the nutty zest of quinoa for this dish.