Wash one cucumber thoroughly under cold water, grate over a colander, wrap in paper towel, and squeeze to remove excess moisture.

In a large mixing bowl, combine the grated cucumber, Greek yogurt, lemon juice, dill, garlic, and season with salt and pepper.

Shred the rotisserie chicken into bite-sized pieces and add to the tzatziki mixture along with diced red onion.

Cover the bowl and refrigerate for at least 30 minutes to allow flavors to meld.

Serve the salad on pita bread, in wraps, or over lettuce; can also be enjoyed with crackers.