Heat grill. In small bowl,combine all ingredients except beef and sour cream; mix well. Brush both sides of steak with oil. Sprinkle seasoning mixture over both sides; with fingers, rub into beef.
When ready to grill, place beef on gas grill over medium-high heat or on charcoal grill 4 to 6 inches from medium-high coals; cover grill. Cook 9 to 12 minutes or until beef is of desired doneness, turning once. Let rest 5 minutes before serving.
To serve, cut beef diagonally into thin slices. Top each serving with 1 tablespoon sour cream.