In a large, shallow bowl or baking dish, combine the soy sauce, olive oil, balsamic vinegar, Worcestershire sauce, honey and Dijon mustard.
Mix until all ingredients are combined.
Mince garlic and add to marinade.
Salt and pepper to taste and stir everything together once more.
Trim the flank steak of any excess fat and place in a dish or large resealable plastic bag with the marinade. Make sure steak is well covered.
Place in refrigerator for at least 4 hours, up to overnight if desired.
Heat up your grill to medium high heat. Place the flank steak on the pre-heated grill and cook for 4 minutes each side, flipping once.
Using a meat thermometer, check to make sure it has reached an internal temperature of 145°F (63°C). Once temperature is reached, remove steak from the grill and let rest for 5 minutes before slicing.
Slice the flank steak against the grain into thin strips. Serve with your favorite side dishes.