Add yogurt, ginger, coriander, paprika, cumin, cardamom, turmeric, saffron, cinnamon, cloves, garlic, and chicken to a resealable plastic bag, be sure chicken is fully covered. Marinate in refrigerator at least 8 hours or overnight, flipping bag a few times.
Take chicken out of bag and dispose of marinade.
Thread chicken, onion, pepper, and zucchini onto 8 wooden skewers.
Spray skewers with cooking spray and season with salt and pepper.
Arrange skewers on a cooking spray coated grill rack and cook 25 minutes or until chicken is fully cooked, turn skewers a few times. Take off of grill.
In the meantime, mix yogurt with tomato, cucumber, sour cream, pepper, cilantro, cumin, and salt.