True London broil is marinated and broiled. Making a smoked London broil adds another layer of flavor to the beef, and in my opinion just makes it better.
A good marinade is what makes the original dish, and when smoking London broil, it's just as important. A marinade adds flavor, improves the tenderness and boosts the moistness of the meat. This London broil marinade is one of my favorites.
Combine the dry ingredients, then mix into the vinegar, soy sauce and
wine. Gradually add the oil, whisking constantly. A good marinade has
the look of salad dressing, with the mixture emulsified and thickened
Place the beef roast in a baking dish or into a gallon size freezer bag. Pour the marinade over the roast, then refrigerate overnight, turning the meat a few times so it's evenly marinated.
When it's time to smoke the London broil, remove it from the fridge, drain off the excess marinade, and allow it to rest at room temperature for an hour or so. Being slightly warmed up means less time in the smoker.
Bring your smoker up to temperature (225-250 degrees Fahrenheit), add wood chips or chunks, and place the roast onto the grate. Good choices for smoker wood include oak or cherry. Oak's my favorite.
It's not necessary to use a lot of smoke on the London broil. A subtle
smokiness is all it needs. If you have a remote thermometer, now's a
good time to use it. Insert the probe into one end, into the thickest
part of the meat.
Continue cooking the London broil until its internal temperature reaches 135 degrees, remove it from the smoker and let it rest for 15 to 20 minutes.
It'll be a perfect medium rare, tender and juicy. If you prefer medium done, leave it in the smoker until it reaches 140 degrees. Slice thinly to serve.