Rather than pointing to one specific cut of beef, a London broil (which has nothing to do with London the city) has come to be a blanket term for a tough cut of steak, typically flank or top round, that is marinated, so that it comes out nice and juicy once cooked over screaming hot heat. While you certainly can take it to your pan, Food Republic spoke with chef Richard Sandoval of Richard Sandoval Hospitality, who recommended grilling it. “Grilling is the best method, as it achieves a deep, flavorful crust,” he said; there’s a reason our recipe for London broil with creamy horseradish sauce calls for this cooking method.
“To maximize the sear,” he continued, “preheat the grill to high heat.” That’ll be between 450 to 500 degrees Fahrenheit. Then, Sandoval went on, “Pat the steak dry and season [it] well with salt and oil, [and] sear three to four minutes per side, then finish over indirect heat.”
Because London broil is a tougher cut of beef, it’s best that you do not cook it past medium, which is 145 degrees Fahrenheit. You should keep a meat thermometer nearby so that you can quickly gauge its temperature — keep in mind carryover cooking; remove your meat from the heat at around 135 to 140 degrees to get the perfect medium.
Marinades are a London broil’s best friend
Along with getting a good sear on high heat, another characteristic that makes a London broil what it is involves marinating the meat for both texture — to help tenderize the meat — and flavor. What you put into your marinade is important, as it must contain an acid to help break down the meat’s fibers, according to chef Richard Sandoval. Common ingredients include soy sauce, vinegar (like balsamic or apple cider) or citrus juice, and Worcestershire sauce, but you can also play around with aromatics like sliced garlic or shallot, sweeteners like brown sugar or honey, herbs like oregano, thyme, and rosemary, and other acidic components, like Dijon mustard or ketchup.
“Marinate [the meat] for at least six hours,” Sandoval instructed, but no longer than 24 hours. If you want to use some of the marinade as a sauce or glaze, take it from the mixture before you pour it over the meat; you don’t want to use the leftover marinade after the raw beef has been sitting in it for hours.
Finally, it’s important to remember that after the marinating and grilling, “Slice against the grain to shorten muscle fibers and improve tenderness,” said Sandoval. To find the grain of a cut of meat, look for the internal lines (or fibers). Then, cut perpendicular to those lines for an extra-tender bite.