In a large bowl, combine the yogurt, olive oil, minced garlic, tomato paste, ground cumin, paprika, ground coriander, chili flakes (if using), salt, and black pepper. Mix thoroughly until smooth. The yogurt tenderizes the chicken, while the spices add deep flavour.

Add the cubed chicken to the marinade, making sure each piece is fully coated. Cover the bowl with plastic wrap and let the chicken marinate for at least 1 hour in the refrigerator, or overnight for the best flavour.

If you’re using wooden skewers, soak them in water for at least 30 minutes before grilling. This prevents them from burning on the grill. For a more traditional touch, metal skewers are often preferred as they evenly transfer heat to the chicken.

Preheat a grill or oven to 400°F (200°C). Lightly oil the grill grates or use a baking tray lined with foil if cooking in the oven.

Thread the marinated chicken cubes onto the skewers, leaving a small gap between each piece for even cooking. Avoid overcrowding to ensure that the chicken cooks evenly and gains a nice char.

Place the skewers on the preheated grill or baking tray. Grill for about 10-12 minutes, turning occasionally to cook all sides, until the chicken is charred and cooked through. If using the oven, bake for about 15-20 minutes, finishing with a quick broil for 2 minutes to achieve a slight char.

Check the internal temperature of the chicken, which should reach 165°F (74°C) to ensure it's fully cooked. Remove the skewers from the heat and let them rest for a couple of minutes to retain their juices.

Serve the Tavuk Şiş hot, garnished with chopped fresh parsley and a side of lemon wedges. Tavuk Şiş pairs beautifully with flatbread, rice, or a fresh salad. A drizzle of extra yogurt sauce or a side of tangy sumac onions enhances the authentic flavors.