London Broil refers to a method of cooking and serving meat - marinated, then grilled or broiled and sliced thin against the grain. You will see many cuts of meat labeled "London Broil" in the supermarket, but our favorite is flank steak.
4 Tablespoons fresh-squeezed lime juice
2 Tablespoons sesame oil
1 1/2 Tablespoons tamari (naturally brewed soy sauce)
3 garlic cloves
Roughly 2-inch piece of ginger, skin removed
1 large or 2 small scallions
1.5 - 2 pound flank steak
Optional: Cilantro leaves and/or additional scallions for garnish
1. Make the marinade:
- Combine the lime juice, sesame oil and tamari in a small bowl.
- Remove the skin from the garlic cloves and grate them on a microplane or other small-holed grater. Add the garlic to the marinade.
- Grate the ginger on the same grater. Use measuring spoons to scoop 1 1/2 teaspoons of the grated ginger into the bowl.
- Slice scallions into small rounds and stir them into the marinade, mixing well to combine all ingredients.
2. Place the flank steak in a gallon-sized Ziplock-style freezer bag and pour the marinade into the bag. Seal the bag, pressing out as much air as possible, so that the steak is evenly covered all over with the marinade. If you don't have a Ziplock-style bag, marinate the steak in a wide dish or bowl instead. (If using a dish or bowl, you should turn the steak over halfway through so that the meat is evenly exposed to the marinade on both sides.) Allow the steak to marinate for about 2 hours.
Note about marinating and refrigeration: if marinating for 2 hours or less, we like to leave the meat at room temperature. Because of the laws of physics and the movement of molecules at different temperatures, the marinade is better able to penetrate the meat at room temperature. However, if marinating for more than 2 hours, the meat must be put in the refrigerator to inhibit bacterial growth.
3. If grilling:
- After 2 hours, set up your grill for high direct heat and allow it to fully heat up. When hot, brush and oil the grate. (Oiling the grate helps make sure the meat won't stick to it. We dip a wad of paper towel in flavorless high-heat oil such as canola, and, wearing oven mitts, use long tongs to brush it against the top of the grate. Careful - if the oil is dripping, the fire may flame up dangerously as you do this! Move quickly and keep your distance to do this safely.)
- When the hot grate has been oiled, lift the flank steak from the marinade, allowing any extra marinade to drip away for a moment, then place it on the grill. If the grill is nice and hot, it should sizzle when you lay it down.
- Close the lid and allow the steak to cook undisturbed for 6-8 minutes (depending on how well done you like your meat). Turn it over and cook on the other side for another 6-8 minutes.
4. Or, if broiling:
- After 2 hours, make sure the oven rack is positioned near the broiler and preheat your broiler to high.
- Set up a pan to broil the steak on: a shallow pan such as a broiler pan or a rimmed cookie sheet works best here. We like to line it with aluminum foil to make cleanup easier. Lay a rack over the aluminum foil so that the meat is slightly elevated from the bottom of the pan. The meat should be about 4 inches from the flame when it goes into the oven.
- Lift the flank steak from the marinade, allowing any extra marinade to drip away for a moment, then place it on the rack.
- Slide the steak into the broiler and broil for 6-8 minutes (depending on how well done you like your meat).
- Remove it from the broiler and turn it over. Put it back in and broil on the other side for another 6-8 minutes.
5. When done, remove the steak from the grill or oven. Transfer it to a plate to rest for 5 minutes (the plate will accumulate the flavorful juices from the meat as it rests). Transfer it to a cutting board and slice it thinly, against the grain, at a 45 degree angle from the cutting board.
6. Optional: scatter cilantro leaves or sliced scallions over the meat as a garnish before serving. Serve sliced meat to each guest, drizzled with the accumulated juices.