In a bowl, whisk together the oil, cumin, paprika, allspice, turmeric, garlic powder and cinnamon. Season with salt and pepper to taste.
Add the chicken thighs, turning to coat. Set aside.
Fire up grill for direct and indirect cooking.
Shake off any excess marinade from the chicken and place the thighs onto the grill over direct heat. Note that the marinade contains oil which might cause flare-ups. If you do encounter a flare-up simply move the chicken to indirect heat until it stops.
Cook chicken until lightly charred and the internal temperature reaches 175 F.
Transfer chicken to platter. Cover and let rest 5 minutes.
For the yogurt sauce
Whisk together the yogurt, lime and garlic. Season with salt and pepper to taste.
For the pitas
Slice chicken into strips and divide between the pitas.
Add chopped mint and cilantro and the yogurt sauce.