Begin by finely grating the cucumber. Wrap tightly in a tea towel and squeeze out excess moisture.

In a mixing bowl, combine Greek yogurt, chopped dill, lemon juice, and minced garlic. Season with salt and pepper to taste.

Shred the rotisserie chicken and add to the tzatziki sauce with diced red onion. Toss until coated.

Gently fold in the prepared cucumber.

Serve on pita bread, over lettuce, or with crackers. Refrigerate leftovers.