Make sure to carefully follow each step of the instructions for the best results :
- Marinate the chicken.
In a large bowl, whisk together the lemon juice, olive oil, garlic, oregano, thyme, paprika, salt, and black pepper. Add the chicken pieces and toss well to coat. Cover and refrigerate for at least 30 minutes and ideally up to 4 hours. Most souvlaki recipes emphasize that the longer the chicken marinates, the more the lemon and oregano penetrate the meat for a deeply flavorful result. - Make the tzatziki.
While the chicken marinates, grate the cucumber for the tzatziki and squeeze out as much liquid as possible using a clean kitchen towel or paper towels. Combine with the yogurt, garlic, lemon juice, olive oil, and dill. Season with salt, stir well, and refrigerate until serving. Squeezing the water from the grated cucumber is essential in all traditional tzatziki recipes to keep the sauce thick and creamy. - Make the cucumber salad.
Combine the sliced cucumbers, red onion, and cherry tomatoes in a bowl. Drizzle with olive oil and vinegar, season with salt and pepper, and toss with fresh dill or parsley. Set aside while the chicken finishes marinating so the flavors have time to come together. - Skewer the chicken.
If using wooden skewers, soak them in water for at least 20 minutes before threading the chicken to prevent burning on the grill. Thread the marinated chicken pieces onto the skewers, leaving a small gap between each piece for even cooking. - Grill the skewers.
Preheat the grill or grill pan to medium-high heat and brush lightly with oil. Cook the skewers for about 3 to 4 minutes per side, turning once or twice, until the chicken is cooked through to 165°F and golden with slight char marks. Most versions cook souvlaki skewers for a total of about 12 to 15 minutes over medium-high heat. - Rest and serve.
Let the skewers rest for 2 to 3 minutes before serving. Plate them alongside the cucumber salad and tzatziki, and finish with lemon wedges and fresh herbs.