The term "London broil" is used to describe several relatively tough cuts of meat, including top round steak, shoulder steak and flank steak. It also describes a cooking method in which the steak is marinated, then grilled and sliced thinly. While grilling is the preferred cooking technique for London broil, other viable techniques include pan-frying, broiling and slow-cooking.
Grill
Marinating for at least four hours results in more tender, flavorful London broil. Use a commercial marinade or make your own from ingredients such as red wine, balsamic vinegar, soy sauce and garlic. Alternatively, use a dry rub containing your choice of seasonings such as chili powder, garlic powder, salt, pepper and paprika instead of marinade. Cook the steak on an oiled grate for about seven to nine minutes for a medium-rare steak.
Slow Cooker
Slow-cooking London broil is an effortless cooking method that produces succulent steak. Begin by placing a sliced onion in the bottom of your slow cooker. Place the steak on top of the onion, and then add ingredients such as sea salt and coarse black pepper, soy sauce, Worcestershire sauce, thyme and whole garlic cloves. Add liquid such as water, beef broth, whiskey, wine, beer, apple cider, tomato juice or a combination of liquids. Cook the steak on low for eight to 10 hours. Check the steak periodically and add more liquid to prevent the meat from drying out and sticking to the bottom of the slow cooker.
Broil
Marinate London broil in your choice of marinades for at least four to six hours before broiling. Without marinade, this relatively tough cut of meat is dry and chewy. After marinating the meat, place the meat on an oiled grill. Broil the steak in a preheated oven, turning the meat once, until it cooks to your liking.
Pan-Fry
Pan-frying is a quick method that causes London broil to be rich and somewhat crispy on the outside but tender and succulent on the inside. To pan-fry London broil, oil a heavy skillet then preheat it until it's nearly smoking. While the pan is preheating, coat the steak with butter or olive oil, and then sprinkle it with salt. Sear the steak quickly until both sides are brown. Turn the burner to low, and then allow the steak to finish cooking until it reaches the desired level of doneness.
Tips
Allow London broil to rest for at least five minutes before carving, as resting allows the rich juices to settle into the steak. Use a sharp carving knife to cut London broil thinly against the grain, as cutting against the grain severs the tough fibers to make the meat more tender.