Massage the steak with 1 tablespoon balsamic glaze then coat with 1 tablespoon olive oil. Wrap in plastic wrap or place in a zipper sealed bag. Let the steak marinate in the refrigerator for 2-4 hours.

Preheat a grill to medium high heat. Grill the steak on both sides until it reaches an internal temperature of 130 F for medium rare, 150 F for medium well and 160 F + for well done. Let the steak rest 5 minutes after cooking before slicing into strips or smaller pieces.

Toss the arugula-spinach mix with the remaining tablespoon olive oil and 1 tablespoon blue cheese crumbles. Top the salad with the sliced steak and avocado. Sprinkle with the remaining tablespoon blue cheese crumbles and additional balsamic glaze as desired.