Rinse the London broil under cold water and dry it with paper towels.
Combine the garlic, shallot, oil, red wine vinegar, sugar, soy sauce, maple syrup/honey, lemon juice, salt, black pepper, red pepper flakes, and oregano in a zipper bag or non-reactive bowl.
Add the London broil, lightly massage the marinade into the beef, and place in the refrigerator to marinate for 6-8 hours.
Preheat your Z-Grills (preferably with branded oak and/or cherry pellets) or other wood pellet grill to 225 degrees Fahrenheit.
Remove the steak from the marinade, lightly pat off any excess, and transfer it to the grates.
Cover the grill’s lid and smoke for 45-50 minutes or until the internal temperature reaches 135 degrees Fahrenheit.
Remove the steak from the grill and rest for 5-10 minutes before slicing.
Finish with salt and black pepper, then serve.