In the large zip lock bag add the yogurt, lemon juice, olive oil, vinegar, garlic, oregano, paprika, cumin, coriander, cayenne, salt, and pepper. Mix and squeeze around until well combined.
Trim any excess fat or gristle from the chicken thighs then add to the bag of marinade. Chill while marinating for at least 45 minutes and up to 8 hours.
Preheat the fire for the rotisserie and set the height for the coals. The temperature should be medium heat, about 300 degrees F (150 degrees C) so the outside is slowly cooked but not burned, yet the center has time to cook.
Place one end of the holding clamp on. Add the chicken thighs one at a time, alternating 90 degrees each time, as the four prongs won’t pass through a single piece of thigh. This will allow the spit to remain balanced. When all the chicken is on, add the second holding clamp, pressing on as firmly as possible to hold all the chicken in place.
Place the spit over the preprepared fire and turn it on to rotate. Continue to monitor the rotisserie while cooking, adjusting the amount of charcoal and height as needed. Check the internal temperature which should be at least 165 degrees F (74 degrees C).
Chicken Gyros
Slice off the edges of the chicken onto a plate. This can be done over the spit leaving the next layer down to brown. Or the rotisserie can be removed, all the chicken removed from the spit, and sliced into smaller pieces.
Cut the pita bread in half and open to make a pocket.
Add the toppings of your choice into the pita, including the tzatziki, tabbouleh, tomatoes, and cucumbers. Add the rotisserie chicken. Continue until all the ingredients used.