In a small bowl, whisk together all of the marinade ingredients until completely combined.
Place steak in a deep dish or in a large Ziploc bag. Pour marinade over steaks, add green onions, and cover (or seal bag) and refrigerate for at least 2 hours and up to overnight.
When ready to cook, prepare your grill for high.
Remove the steak from the marinade and place steak on the hot grill. Dispose of marinade. Grill for about 4-6 minutes per side, or until done to your liking (a meat thermometer should read 125 to 130°F for rare, 140°F for medium rare, and 150°F for medium).
When the steak has cooked to your preferred level of doneness, remove from the grill and place on a cutting board. Cover with aluminum foil to hold in the heat while the steak rests for 10 to 15 minutes.
Cut the steak across the grain of the meat, at a steep diagonal, so that the slices are wide. A serrated knife works best for this.