Cook and shred the chicken breast, then allow it to cool completely.
In a large mixing bowl, combine the Greek yogurt, minced garlic, fresh lemon juice, chopped dill, olive oil, salt, and pepper. Whisk until you have a smooth, creamy tzatziki-inspired dressing.
Lightly salt the diced cucumber pieces and let them sit in a colander for 5 minutes, then gently press out excess moisture with a paper towel.
Add the cucumber, cherry tomatoes, and cooled shredded chicken to the yogurt dressing. If using optional ingredients like red onion, feta cheese, or kalamata olives, add them now.
Gently fold everything together until the chicken and vegetables are evenly coated with the tzatziki dressing.
Taste and adjust the seasoning with additional salt, pepper, or lemon juice as needed.
Cover and refrigerate for at least 15 minutes (though 30 minutes to 1 hour is ideal) to allow the flavors to meld together.
Before serving, give the salad a gentle stir and garnish with extra fresh dill or a drizzle of olive oil if desired.
