Preheat grill or grill pan to high heat. In a bowl, combine yogurt and spices. Add Chicken and toss to combine. Oil the grill and cook chicken over high heat, turn once. (6-8 Minutes per side, depending on the thickness of the chicken breast). Internal temp should reach 165 degrees F. Remove cooked chicken to a plate and allow to rest for 5 minutes. Serve with Sheppard's Salad and couscous.