I don’t care what your butcher says or the label on the tray of meat says, London Broil is NOT a cut of meat. It is a cooking method.
I have seen butchers label everything from flank steak to porterhouse "London Broil." NOT! London broil is usually a large thick cut steak or small roast from a lean hardworking muscle, marinated and broiled or grilled, and cut in thin slices across the grain.
The odd part is that the term broil is not commonly used in London. Over there, they call it a "grill" of all things.
To make London Broil, I use chuck roasts, top round, sirloin, or coulotte. I make a concentrated, intensely flavorful brinerade with soy sauce as the salt source. I leave it in the liquid for several hours, overnight sometimes. And then I break several Meathead Methods.
Normally we leave oil out of marinades because it cannot penetrate meat, which is 70% water. Normally we pat meat dry to encourage browning. A wet surface steams, and if there is sweetness, the surface can burn. With London Broil, the surface steams and helps cool the thick cut of meat so it doesn’t burn. The result is a beautiful dark slab that smells heavenly.
London Broil Recipe
Here's how to make a London Broil the right way.
Course. Entree. Dinner.
Makes. 4 servings
Takes. 3 hours to marinate minimum and 60 minutes to cook depending on the energy from the grill and how often you baste.
2 pounds beef steak, 1 to 2” thick
1/4 cup inexpensive salad grade balsamic vinegar
5 tablespoons dark soy sauce
2 tablespoons vegetable oil
1 teaspoon toasted sesame oil
4 cloves garlic
2 tablespoons Italian seasoning blend
1 teaspoon black pepper
1 teaspoon gochujang or another hot sauce or pepper paste
About the beef. For London Broil I usually select a thick lean cut such as top round or sirloin or occasionally a chuck roast.
About the gochujang. This is a spicy hot and salty Korean-style miso paste but you can use another hot sauce if you don't have it. Don't worry too much about the heat. Each slice of meat has only a 1/4" wide layer of marinated meat on the surface so it will not be too hot.
Optional. If you are using a very lean cut, make a horseradish compound butter and place some on the hot meat so it melts. Just soften a stick of butter and mix in 2 tablespoons of horseradish or an herb, then chill.
1) Shopping. Try to buy a slab that is uniformly thick so it cooks evenly, unless you have someone who wants it slightly overcooked. Then a tapered end has his or her name on it.
2) Trim any fat cap and silverskin off the meat
3) Marinate the balsamic, soy, oils, garlic (press it or mince it first), seasoning and pepper in pan or a large zipper bag and slide the meat in. Place a zipper bag in a bowl in case it leaks. Chill for 4 to 24 hours. Every 30 minutes to an hour, roll it around so all sides of the meat stay wet.
4) Fire up. Set up your grill for 2-zone cooking and get the hot zone really hot. Place the meat in the indirect zone and let it warm until it hits about 125°F in the thickest part. Then move it over the high heat, lid up, and flip often until it gets really dark all over but not burned. Slice across the grain about ¼” thick, and serve.