Combine first 4 ingredients in a small bowl; stir well. Place steak and 1/4 cup hoisin sauce mixture in a large zip-top plastic bag; seal bag, and marinate in refrigerator 6 hours, turning bag occasionally. Cover remaining 1/2 cup hoisin sauce mixture, and refrigerate while steak marinates.
Remove steak from bag; discard marinade. Place steak on a broiler pan coated with cooking spray. Broil 5 minutes on each side or until desired degree of doneness. Let steak stand 5 minutes.
While steak stands, combine spinach and next 4 ingredients in a large bowl. Drizzle with 1/4 cup reserved hoisin sauce mixture; toss gently to coat. Cut steak diagonally across grain into thin slices.
Place 2 1/2 cups salad on each of 4 plates; divide steak evenly among salads. Drizzle 1 tablespoon hoisin sauce mixture over each salad.