Begin by grating one cucumber until you have about a cup. Squeeze out excess moisture using a clean towel to ensure the tzatziki isn't watery.

In a mixing bowl, combine the grated cucumber with one cup of plain Greek yogurt, a handful of chopped fresh dill, the juice of one lemon, and two minced garlic cloves. Season generously with salt and pepper, then mix until fully combined.

Take your rotisserie chicken and carefully pull it apart, shredding the meat into bite-sized pieces. Transfer the chicken into the bowl with the tzatziki mixture. Use a spatula to gently fold and toss until the chicken is well coated.

Add half a cup of finely diced red onion to the mixture and stir gently to combine. Taste and adjust seasoning with salt and pepper if needed.

Serve the salad as is, over mixed greens, or in warmed pita bread. Optionally add sliced cherry tomatoes.