Combine first 7 ingredients in a small skillet over medium heat; cook 2 minutes or until fragrant, stirring constantly. Let cool. Place spice mixture in a spice or coffee grinder, and process mixture until finely ground.
Combine spice mixture, yogurt, and next 5 ingredients (through garlic) in a large zip-top plastic bag. Add fish, tossing to coat; seal and marinate in refrigerator for 2 hours, turning occasionally. Remove fish from bag; discard marinade.
Thread 5 pieces of fish onto each of 6 (12-inch) skewers. Place skewers on a broiler pan coated with cooking spray; broil 7 minutes on each side or until done. Arrange the skewers on a platter.