In a large mixing bowl, combine plain whole-milk yogurt, olive oil, minced garlic, lemon zest, and lemon juice. Add the spice blend of cumin, coriander, smoked paprika, turmeric, cinnamon, and a pinch of salt and pepper. Stir until fully combined.

Add the boneless, skinless chicken thighs to the marinade, ensuring each piece is thoroughly coated. Marinate for 30 minutes at room temperature or up to 12 hours in the fridge.

Slice an onion and scatter the pieces evenly in the bottom of your slow cooker.

Place the marinated chicken on top of the layer of onions. Cover and set slow cooker to LOW for 6–7 hours or HIGH for 3–4 hours.

After cooking, transfer the chicken to a cutting board and shred it using two forks. Mix in some slow cooker juices for added moisture.

Preheat your broiler. Spread the shredded chicken on a foil-lined baking sheet, drizzle with olive oil, and broil for 5-8 minutes, turning halfway.

Serve in warm pita bread with fresh toppings like diced tomatoes, cucumbers, or garlic sauce.