Grilling London broil demands high heat for a perfect sear, then careful resting to let the juices redistribute. If you’re wondering how to cook london broil on the grill, you’ve come to the right place. This cut can be tough if mishandled, but with the right technique, it turns into a tender, flavorful steak that rivals any pricier cut. Let’s get straight to it.
London broil isn’t actually a cut of meat. It’s a cooking method. Most often, it refers to a top round or flank steak. These cuts are lean and can be chewy. The key is to cook them hot and fast, then slice them thin against the grain. That’s the whole secret.
You don’t need fancy equipment. A gas or charcoal grill works fine. A meat thermometer helps a lot. And a sharp knife is non-negotiable for slicing. Ready to fire up the grill? Let’s break it down step by step.
Understanding London Broil
First, know what you’re buying. London broil is usually a top round steak, about 1 to 2 inches thick. It’s a hardworking muscle from the cow’s hind leg. That means it’s lean and full of connective tissue. Cooked wrong, it’s like shoe leather. Cooked right, it’s a revelation.
Some grocers label flank steak as London broil too. Either way, the rules are the same. High heat, quick cook, thin slices. Don’t overthink it.
Why Grilling Works Best
Grilling gives you direct, intense heat. That’s perfect for searing the outside while keeping the inside medium-rare. A cast-iron pan works too, but the grill adds smoky flavor you can’t get indoors. Plus, it’s summer. Who wants to heat up the kitchen?
The grill marks look great. But more importantly, the high heat creates a crust that locks in moisture. That crust is what makes London broil taste like a steakhouse meal.
How To Cook London Broil On The Grill
Now for the main event. This section covers everything from prep to plating. Follow these steps, and you’ll nail it every time.
Step 1: Choose The Right Cut
Head to the butcher counter. Look for a London broil that’s at least 1 inch thick. Thicker is better. A 1.5-inch cut gives you more room for error. Avoid anything under 3/4 inch—it’ll dry out before it sears.
- Top round: most common, lean, needs marinating
- Flank steak: slightly more flavor, also lean
- Look for even thickness so it cooks uniformly
- Check for good marbling—small white flecks of fat
If you see a lot of fat cap on one side, trim it to about 1/4 inch. Too much fat can cause flare-ups on the grill.
Step 2: Tenderize And Marinate
London broil is tough. You need to break down those fibers. Use a meat mallet or the back of a heavy knife to pound it to even thickness. Don’t go crazy—just a few firm whacks.
Marinating is optional but recommended. An acidic marinade helps tenderize the meat. Use something with vinegar, citrus, or wine. Add oil, garlic, herbs, and a little salt. Let it sit for 2 to 4 hours. Overnight is fine, but not longer—acid can turn the meat mushy.
Here’s a simple marinade:
- 1/4 cup soy sauce
- 2 tablespoons olive oil
- 2 tablespoons red wine vinegar
- 3 cloves garlic, minced
- 1 teaspoon black pepper
Pat the meat dry before grilling. Wet meat won’t sear properly.
Step 3: Preheat The Grill
Get your grill screaming hot. For gas, turn all burners to high and close the lid for 10 minutes. For charcoal, light a full chimney and let the coals turn white-hot. You want a temperature of 450°F to 500°F. If you can hold your hand 5 inches above the grate for only 2 seconds, it’s ready.
Clean the grates with a wire brush. Then oil them lightly. Use a paper towel dipped in oil and held with tongs. This prevents sticking.
Step 4: Season The Meat
Right before grilling, season the London broil generously. Use kosher salt and fresh cracked black pepper. Don’t be shy. The salt draws out moisture and helps form that crust. If you used a marinade, you might not need extra salt. Taste the marinade first.
Add any dry rub you like. A mix of paprika, garlic powder, onion powder, and cayenne works great. But keep it simple. The beef flavor should shine.
Step 5: Grill Over High Heat
Place the London broil on the hottest part of the grill. Close the lid. Cook for 4 to 5 minutes per side for medium-rare. Flip only once. Use tongs, not a fork—piercing the meat lets juices escape.
Here’s a timing guide for a 1-inch thick steak:
- Rare: 3 minutes per side (120°F internal)
- Medium-rare: 4 minutes per side (130°F)
- Medium: 5 minutes per side (140°F)
- Medium-well: 6 minutes per side (150°F)
For thicker cuts, add a minute or two per side. Always use a meat thermometer for accuracy. Insert it into the thickest part, avoiding bone.
Watch for flare-ups. If flames get too high, move the meat to a cooler part of the grill. You want sear, not char.
Step 6: Rest The Meat
This step is crucial. Don’t skip it. Remove the London broil from the grill and place it on a cutting board. Tent loosely with foil. Let it rest for 10 minutes. That’s half the cooking time.
Resting lets the juices redistribute. If you cut into it right away, all those flavorful juices run out onto the board. Your steak ends up dry. Be patient.
The internal temperature will rise about 5°F during resting. So pull it off the grill at 125°F for medium-rare. It’ll climb to 130°F.
Step 7: Slice Against The Grain
Find the grain. It’s the lines running through the meat. You want to cut perpendicular to those lines. That shortens the muscle fibers, making each bite tender.
Slice thin—about 1/4 inch thick. Use a sharp chef’s knife or carving knife. Angle the knife slightly for wider slices if you prefer. But thin is the key.
If you cut with the grain, you’ll get long, chewy strips. Nobody wants that.
Step 8: Serve Immediately
Arrange the slices on a warm platter. Spoon any accumulated juices over the top. Serve right away while it’s still hot. London broil cools fast, so don’t dawdle.
Pair it with simple sides. Grilled vegetables, a crisp salad, or roasted potatoes work well. The steak is the star. Let it shine.
Common Mistakes And How To Avoid Them
Even experienced cooks mess up London broil. Here are the most common pitfalls.
Overcooking
This is the number one mistake. London broil is lean. Cook it past medium, and it turns into jerky. Use a thermometer. Pull it at 125°F for medium-rare. If you like it more done, that’s your call. But know that medium-well is a gamble.
Skipping The Rest
I get it. You’re hungry. But cutting into the meat right off the grill ruins it. Those 10 minutes of rest are non-negotiable. Set a timer if you have to.
Cutting With The Grain
This is a texture killer. Always slice against the grain. Look at the lines before you cut. If you’re not sure, make a small cut and check. It’s better to be safe than sorry.
Using A Cold Steak
Take the London broil out of the fridge 30 minutes before grilling. A cold steak cooks unevenly. The outside burns while the inside stays raw. Let it come to room temperature first.
Not Oiling The Grate
Lean meat sticks to a dry grill. Oil the grates well. Also oil the steak itself with a light coat of oil. That helps prevent sticking and promotes even browning.
Variations And Flavor Ideas
Once you master the basic technique, experiment with different flavors. Here are a few ideas.
Asian-Inspired London Broil
Marinate in soy sauce, ginger, garlic, and sesame oil. Add a splash of rice vinegar. Grill as usual. Serve with steamed rice and stir-fried bok choy. Sprinkle with sesame seeds.
Spicy Southwest Style
Use a rub with chili powder, cumin, smoked paprika, and cayenne. Marinate in lime juice and oil. Grill hot. Slice and serve with salsa verde and warm tortillas.
Herb And Garlic Butter
After grilling, top the rested steak with a pat of compound butter. Mix softened butter with minced garlic, chopped parsley, and thyme. The butter melts over the hot meat, adding richness.
Balsamic Glaze
Marinate in balsamic vinegar, olive oil, and rosemary. After grilling, drizzle with a balsamic reduction. It adds sweetness and tang. Great with arugula salad.
Frequently Asked Questions
Here are answers to common questions about grilling London broil.
How Long Should I Grill London Broil?
For a 1-inch thick steak, grill 4 to 5 minutes per side for medium-rare. Adjust based on thickness and desired doneness. Use a meat thermometer for accuracy.
Can I Cook London Broil Without A Marinade?
Yes. London broil can be grilled without marinating. Just season generously with salt and pepper. The high heat sear creates flavor. But marinating adds tenderness and extra taste.
What Temperature Should London Broil Be?
For medium-rare, aim for 130°F after resting. Pull it off the grill at 125°F. The temperature will rise during resting. For medium, pull at 135°F.
Why Is My London Broil Tough?
It’s likely overcooked or sliced with the grain. London broil is a lean cut. Overcooking dries it out. Always slice thin against the grain. Marinating can also help tenderize.
Can I Grill London Broil From Frozen?
Not recommended. Thaw it completely in the fridge first. Grilling from frozen leads to uneven cooking. The outside burns while the inside stays raw. Plan ahead.
Final Tips For Perfect London Broil
You’ve got the steps. Now here are a few extra pointers to ensure success.
Let the meat rest after marinating. Pat it dry before seasoning. Don’t overcrowd the grill—give each piece space for proper searing. Use a thermometer every time. Trust it over guesswork.
If you’re using charcoal, set up a two-zone fire. One side hot for searing, one side cooler for finishing. This gives you control if the steak needs more time without burning.
For a gas grill, leave one burner on high and turn the others to medium. That way you have a hot zone and a cooler zone. Move the steak if needed.
Don’t press down on the steak with a spatula. That squeezes out juices. Let the grill do the work. Flip once and leave it alone.
Slice just before serving. Sliced meat cools quickly. If you’re not eating right away, keep the whole steak warm under foil, then slice at the table.
Leftovers? Slice thin and use in sandwiches, salads, or stir-fries. Cold London broil is great on a salad with a tangy vinaigrette. Or reheat gently in a skillet with a little broth.
Grilling London broil is a skill worth mastering. It’s affordable, impressive, and delicious when done right. With high heat, careful timing, and proper slicing, you’ll get tender, juicy results every time. Fire up the grill and give it a try. You’ll wonder why you didn’t do it sooner.