London Broil with Garlicky Herb Butter

published Dec 23, 2021
London Broil Recipe

This steak dish is prepared by marinating and then broiling flank or top round.

Serves4

Prep10 minutes

Cook8 minutes to 15 minutes

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London Broil (a beef dish made by broiling marinated beef, then cutting it across the grain into thin strips) sliced on a wooden cutting board with melted butter and herbs on top.
Credit: Laura Rege

How do you turn a leaner cut of steak into a restaurant-worthy main? Easy. London broil. It’s a technique for cooking steak — usually something lean, like flank steak and top round — that requires marinating the meat (to tenderize it!) then broiling it for fast, hot cooking. Despite its name, it’s as American in origin as it can be, but “London” does give it a little cache when you set it down on the table.

For perfect results every time, follow these important tips.

  • Don’t skip the marinade. Our marinade hits almost all of the flavor notes. Lemon juice adds acidity, oil brings richness, Worcestershire and soy sauce offer a nice salty umami, sugar balances out bitterness, and Dijon mustard and garlic give bold flavor. If you’re missing spice, add red pepper flakes or hot sauce. Marinate the steak for at least one hour or up to 6 for the best texture.
  • Heat up the broiler. It wouldn’t be a London broil without, well, a broiler. The broiler provides just the right kind of high heat that you would get from searing the steak in a pan or placing it on a grill without as much effort. Make sure to get the broiler nice and hot before placing the steak in the oven. 
  • Line the tray with foil. This step won’t affect the cooking, but it will change everything when it comes time to do the dishes! Any juices that might drip out, dry out, and caramelize under the heat of the broiler are contained on the foil, saving a lot of elbow grease later on.
  • Pat the meat dry. Excess moisture is the broiler’s enemy. It causes the meat to steam rather than sear, and steaming means less flavor. Pat the steak dry well to avoid this.
  • Let the meat rest. As meat rests (aka sits on a cutting board after being cooked and before being sliced) the juices lock back into the steak. Slice too early and you’ll have a cutting board full of flavorful and juicy meat juices that go to waste. We recommend waiting 15 minutes.
  • Slice across the grain. Always important with steak, but especially so with leaner cuts, slice the steak across the grain, which will make the whole eating experience way less chewy and infinitely more enjoyable. 

How to Tenderize London Broil

Use a zesty marinade to tenderize the meat. Some recipes also call for pounding the meat with a meat mallet to tenderize it further and help the meat absorb the marinade. You don’t necessarily need to thin the meat out, although you could make it a more even thickness.

Credit: Laura Rege

What to Serve with London Broil

Treat this just like any steak dinner. Serve it with vegetables sides like mashed potatoes, Brussels sprouts, green beans, or scalloped corn

Tips for Marinating London Broil

I like using a zip-top bag because it really helps surround the meat with the marinade. To do this with the most success, make sure to remove excess air and place the sealed bag on a rimmed plate or baking sheet (just in case any juices drip out). 

London Broil Recipe

This steak dish is prepared by marinating and then broiling flank or top round.

Prep time 10 minutes

Cook time 8 minutes to 15 minutes

Serves 4

Nutritional Info

Ingredients

  • 3

    medium lemons

  • 3 cloves

    garlic, divided

  • 6 sprigs

    fresh thyme

  • 1/4 cup

    olive oil

  • 1/4 cup

    soy sauce, preferably light

  • 2 tablespoons

    packed light brown sugar

  • 1 tablespoon

    Dijon mustard

  • 1 3/4 pounds

    flank steak

  • 4 tablespoons

    (1/2 stick) unsalted butter

  • 1/4 cup

    packed fresh parsley leaves

  • 1 teaspoon

    kosher salt, divided

  • 1/2 teaspoon

    freshly ground black pepper, divided

Instructions

  1. Prepare the following, adding each to the same medium bowl as it is completed: Juice 3 medium lemons until you have 1/4 cup. Thinly slice 2 of the garlic cloves. Pick the leaves from 6 fresh thyme sprigs (about 1 tablespoon). Add 1/4 cup olive oil, 1/4 cup soy sauce, 2 tablespoons packed light brown sugar, and 1 tablespoon Dijon mustard, and whisk until well-combined.

  2. Place 1 3/4 pounds flank steak in a large zip-top bag and pour in the marinade. Massage to evenly coat the steak. Press out the excess air and seal the bag, then place on a small rimmed baking sheet or large rimmed plate, arranging the steak out as flat as possible. Marinate at room temperature for 1 hour or refrigerate for up to 6 hours. If refrigerated, let the meat come to room temperature before cooking.

  3. Meanwhile, place 4 tablespoons unsalted butter in a medium bowl and let sit at room temperature until softened, about 1 hour. Finely chop 1/4 cup packed fresh parsley leaves and add to butter. Finely grate the remaining 1 clove garlic into butter. Season with 1/4 teaspoon of the kosher salt and and 1/4 teaspoon of the black pepper, and mash and stir until combined.

  4. Arrange a rack in the closest position to the broiler and heat the oven to broil on high. Line a rimmed baking sheet with aluminum foil. Remove the steak from the marinade and pat dry with paper towels, brushing off any garlic or thyme. Season the steak all over with the remaining 3/4 teaspoon kosher salt and 1/4 teaspoon black pepper.

  5. Place the steak on the baking sheet. Broil until golden-brown, 4 to 5 minutes. Flip and broil until the second side is browned and the thickest part registers 120 to 125°F for medium-rare, 3 to 8 minutes more. Transfer to a clean cutting board and let rest for 10 minutes, then flip and let rest for 5 minutes more (tent loosely with aluminum foil if your kitchen is cold).

  6. Slather the butter mixture over the top of the steak, slice across the grain, and serve.

Recipe Notes

Storage: Refrigerate leftovers in an airtight container for up to 3 days.