Combine yogurt and spices in medium bowl. Add chicken and stir to coat. Melt margarine in large nonstick skillet over medium-high heat and cook chicken, in two batches, turning once, until golden brown, about 4 minutes. Place chicken in slow cooker.
Add remaining ingredients except half and half cream to slow cooker. Cover and cook on HIGH 3-1/2 hours. Stir in half and half cream and cook 30 minutes until chicken is very tender.** Break chicken into bite-size pieces with wooden spoon.
Serve, if desired, with steamed cauliflower, chick peas, hot cooked rice and sprinkled with chopped cilantro.