For the marinade, in a small bowl combine yogurt, 2 teaspoons of the seasoning plus garlic; mix well. Spread over both sides of steak. Place steak in a large dish; cover and refrigerate at least 8 hours.
Preheat broiler to high.
Remove steak from marinade; discard marinade. Sprinkle steak with remaining 1/2 teaspoon seasoning.
Place steak on a broiler pan rack or nonstick baking pan. Broil 3 to 4 minutes per side (145°F for medium-rare) or to desired doneness. Transfer steak to a cutting board; let stand 10 minutes.
Cut steak across the grain into thin slices, and serve.
