In a ziplock bag, combine minced garlic, white wine vinegar, lemon juice, olive oil, dried oregano, salt, and black pepper. Add the chicken thighs, seal it, and massage gently. Marinate in the refrigerator for at least 2 hours, or up to 24 hours.

While the chicken marinates, prepare the tzatziki. Grate cucumbers and squeeze out excess moisture. Combine with Greek yogurt, lemon juice, olive oil, minced garlic, salt, and black pepper. Stir well and let rest in the fridge for at least 20 minutes.

In a large bowl, combine diced tomatoes, diced cucumbers, chopped onion, and parsley. Season with salt and pepper to taste, then gently toss.

Preheat your grill to medium-high heat or heat olive oil in a frying pan. Remove chicken from the fridge, shaking off excess marinade. Cook for 2 to 3 minutes on each side until golden brown and fully cooked, reaching an internal temperature of 165°F (74°C).

Once cooked, transfer chicken to a plate and let it rest for about 5 minutes. Optionally, cut into strips before serving.

Warm pita breads or flatbreads. Lay a piece flat, spoon salad down the center, add slices of chicken, and top with tzatziki. Roll up tightly and secure for easy handling.