Egyptian Style Chicken Kebabs

Combine yogurt, salt, turmeric, mustard, curry powder, cardamom, lemon juice and vinegar. Place chicken in a medium bowl and pour mixture over top. Toss to coat and let stand for 30 minutes. Remove chicken pieces and thread onto skewers alternating with the onion and tomato pieces. Preheat grill. Place kebabs on grill and cook for about 10 minutes or until done. Brush with marinade half way through the cooking time. Remove and serve. Traditionally garnished with tomato slices, green pepper rings and parsley.