How To Grill A London Broil | Juicy Slices, Bold Crust

Grill London broil hot and fast to a pink center, then rest and slice thin against the grain for tender bites.

London broil is one of those cuts that can make you look like a grill wizard… or leave you chewing for days. The difference isn’t luck. It’s a short list of moves you can repeat every time: pick the right steak, season it with purpose, hit high heat, then slice it the right way.

This is a lean, long-grain cut (often top round or flank, depending on what your store labels as “London broil”). It won’t forgive low heat for an hour. Treat it like a thick steak that wants a hard sear and a gentle finish. Then you’ll get that dark, beefy crust on the outside and clean, juicy slices inside.

What London Broil Means At The Store

“London broil” is often a label, not one single cut. In many groceries it’s top round steak, sometimes flank. Both can taste great grilled, yet they behave a bit differently.

Top Round London Broil

Top round is lean and tight-grained. It does best with a marinade or at least a salty rest before grilling. It also likes being cooked to medium-rare or medium, then sliced thin.

Flank London Broil

Flank has bigger, more visible grain and a deeper beef bite. It still needs thin slicing against the grain, yet it can feel more tender than top round when cooked and sliced well.

Choose The Steak And Trim It Right

Look for a piece that’s 1 to 1 1/2 inches thick if you can. Too thin and it overcooks before you get a real crust. Too thick is fine, yet you’ll want a two-zone fire so you can finish it without burning the outside.

What To Look For

• Even thickness: it cooks more evenly, so you don’t end up with one end well-done.
• Clean edges: a few ragged flaps can burn early and taste bitter.
• Some surface fat is fine: thick caps are rare on these cuts, yet a little fat can help flavor.

Quick Trim

Pat the steak dry. Trim only loose, thin flaps and any hard, waxy fat. Don’t go hunting for “silver skin” like a tenderloin job. You can leave most of the surface intact and let heat do the work.

Set Your Flavor Plan

London broil can taste plain if you only sprinkle salt at the last second. Give it a plan: either a marinade that brings salt plus acid, or a dry brine that uses salt and time.

Option 1: Simple Marinade (Best For Top Round)

This style adds flavor and helps the surface brown. Use it when the steak is lean and tight.

• Olive oil
• Soy sauce
• Worcestershire
• Garlic
• Black pepper
• Lemon juice or red wine vinegar

Marinate 2–12 hours in the fridge. If you go longer, keep the acid modest so the surface doesn’t get mealy.

Option 2: Dry Brine (Fast, Clean, Steakhouse Style)

Salt the steak all over and leave it uncovered on a rack in the fridge for 2–24 hours. This seasons deeper than a last-minute sprinkle and dries the surface for better searing.

Food-Safe Marinade Handling

Marinate in the fridge, not on the counter. Toss used marinade that touched raw meat, or boil it hard before brushing it on later. The USDA’s guidance on marinating and food safety lays out the basics in plain terms.

Grilling A London Broil With High Heat And A Calm Finish

Here’s the core idea: sear first, then finish to temp. That can be done on gas or charcoal. You just need two zones: one hot side, one cooler side.

Gas Grill Setup

Preheat with the lid closed for 10–15 minutes. Run one side on high and the other on medium-low (or off). You want a ripping hot spot for searing and a safer spot to coast to the center temperature.

Charcoal Grill Setup

Bank the coals to one side for a strong direct zone. Leave the other side with few or no coals. Put the lid on and let the grate heat well before the steak goes down.

How Hot Is “Hot”

You’re aiming for strong sear heat. A clean grate and a dry steak help more than chasing a perfect thermometer reading at the grate. If you hold your hand 5 inches above the hot side and you have to pull away in 2–3 seconds, you’re in the right range.

Recipe Card: Grilled London Broil

Grilled London Broil

Servings: 6

Prep time: 15 minutes (plus marinating or salting time)

Cook time: 10–18 minutes

Rest time: 8–12 minutes

Ingredients

• 1 London broil steak (2–3 lb), about 1 to 1 1/2 inches thick
• 1 1/2 tsp kosher salt (use 1 tsp if using soy sauce marinade)
• 1 tsp black pepper
• 1 tsp garlic powder (or 2 grated garlic cloves)
• 1 tbsp neutral oil for the grate and steak surface

Optional Marinade

• 3 tbsp soy sauce
• 2 tbsp olive oil
• 1 tbsp Worcestershire sauce
• 1 tbsp lemon juice or red wine vinegar
• 2 garlic cloves, grated
• 1/2 tsp black pepper

Instructions

1. Pat the steak dry. If using the marinade, mix it, add the steak, and refrigerate 2–12 hours. If dry brining, salt the steak and refrigerate uncovered 2–24 hours.
2. Preheat the grill for two-zone cooking: one hot side for searing, one cooler side for finishing.
3. Oil the grate. Brush a light coat of oil on the steak surface. Season with pepper and garlic (skip extra salt if your marinade is salty).
4. Sear over the hottest zone with the lid closed between flips. Cook 3–5 minutes per side to build a dark crust.
5. Move the steak to the cooler zone. Close the lid and cook until it reaches your target internal temperature (use the temperature table below).
6. Rest the steak 8–12 minutes on a board. Slice thin against the grain at a slight angle. Serve right away.

Notes

• Slice thin. Thick slices can taste tough even when cooked right.
• If flare-ups start, slide the steak to the cooler side, close the lid, and let the heat steady out.
• A meat thermometer is the cleanest path to repeatable results.

Temperature Targets That Keep It Tender

London broil turns chewy fast once it pushes past medium. If you like it more cooked, slice thinner and cut across the grain with care.

Pull Temps And Carryover Heat

Pull the steak a bit early. It rises during the rest. A thicker piece can climb 5–10°F while it sits.

Food safety guidance for whole cuts of beef points to 145°F with a rest time. The USDA’s steaks and chops temperature guidance is a solid reference when you’re planning doneness and rest time.

Doneness Chart For Grilled London Broil

Use this as a working target, then adjust by your taste and thickness. The “pull” numbers help you land where you want after resting.

TABLE #1 (after ~40% of article)

Goal	Pull Temp	Finish Notes
Rare	120–125°F	Soft center, thin slicing matters most
Medium-rare	128–132°F	Best balance of tenderness and beef flavor
Medium	135–140°F	Still pleasant if sliced thin across the grain
Medium-well	145–150°F	Lean cuts can feel firm; slice paper-thin
Well-done	155°F+	Expect chew; serve with a sauce and extra rest
Thin Steak (Under 1 inch)	Use sear-only method	Skip long finishing; it overcooks fast
Thick Steak (Over 1 1/2 inches)	132–138°F	Sear hard, then longer on cool side with lid closed
Rest Time	8–12 minutes	Juices settle, carryover heat finishes the center

How To Grill A London Broil Step By Step

This is the repeatable flow. Keep it simple and you’ll get better results than chasing tricks.

Step 1: Dry The Surface

Moisture is the enemy of crust. Pat the steak dry, even if it came from a marinade. Wet meat steams and turns gray before it browns.

Step 2: Oil The Grate, Not The Fire

Use tongs and a paper towel with a bit of oil to wipe the hot grate. This helps release and keeps the surface clean for searing.

Step 3: Sear With The Lid Closed

Put the steak on the hottest zone. Close the lid. Flip after 3–5 minutes, once it releases with a firm tug. Close the lid again. You’re building color fast without drying the center.

Step 4: Finish On The Cooler Zone

Move it to the cooler side when the outside looks right. Insert a thermometer from the side into the thickest part. Close the lid and let the heat do steady work.

Step 5: Rest, Then Slice The Right Way

Resting is non-negotiable if you want juicy slices. Move the steak to a board and wait 8–12 minutes.

How To Spot The Grain

Look for long lines running across the steak. Those are muscle fibers. You want to cut across them, not along them.

How To Slice

Slice thin, at a slight angle, straight across the grain. If the steak is wide, cut it into two or three shorter pieces first, then slice those pieces across the grain. This one move can turn a “tough cut” into a weeknight favorite.

Timing Tips That Make The Cook Feel Easy

Grill time depends on thickness and heat. Instead of clinging to one number, use a time window and watch the thermometer.

Common Time Windows

• 1-inch steak: 3–4 minutes per side to sear, then 2–6 minutes to finish
• 1 1/2-inch steak: 4–5 minutes per side to sear, then 4–10 minutes to finish
• 2-inch steak: 5–6 minutes per side to sear, then 8–16 minutes to finish

When The Outside Browns Too Fast

Slide the steak to the cooler side sooner. Close the lid and let it finish there. You’ll still get flavor from the sear you already built.

Seasoning Ideas That Fit London Broil

This cut loves bold, simple flavors. You don’t need a long list of spices. You need a couple that show up on a hot grill.

Steakhouse Blend

Salt, coarse black pepper, garlic powder, and a pinch of smoked paprika. Finish with a squeeze of lemon after slicing.

Herb And Butter Finish

Mix softened butter with chopped parsley, grated garlic, and a pinch of salt. Put a small dollop on the sliced steak so it melts into the warm surface.

Chimichurri-Style Spoon Over

Chopped parsley, olive oil, red wine vinegar, garlic, salt, pepper, and crushed red pepper. Spoon it over after slicing for a bright counterpoint to the crust.

TABLE #2 (after ~60% of article)

Problem	What Caused It	Fix Next Time
Tough, chewy slices	Sliced with the grain or too thick	Slice thin across the grain at an angle
Dry center	Cooked past medium on a lean cut	Pull earlier, rest longer, use a thermometer
Pale surface	Steak went on wet, grill not hot enough	Pat dry, preheat longer, sear on hot zone
Burned edges	Thin flaps or sugar-heavy marinade	Trim loose bits, keep sugar low, move to cool zone
Sticks to the grate	Dirty grate or flipped too soon	Clean and oil grate, wait for release
Uneven doneness	One end thicker, single heat zone	Two-zone setup, rotate, finish on cooler side
Weak flavor	Under-seasoned, no salt time	Dry brine 2–24 hours or use a salty marinade

Serving Ideas That Keep It Juicy On The Plate

London broil shines when you treat it like sliced steak, not like a thick roast. Serve it warm, sliced, and paired with something that likes the juices.

Easy Pairings

• Grilled onions and peppers
• Roasted potatoes or smashed potatoes
• Simple green salad with vinaigrette
• Rice or couscous that soaks up juices

Sandwich And Leftover Moves

Chill leftovers first, then slice even thinner. Cold slicing is cleaner. Warm gently in a covered pan with a splash of broth, or pile slices into a toasted roll with onions and a sharp sauce.

Small Details That Separate “Good” From “Nailed It”

If you want the version that makes people ask what you did, these are the details that pay off.

Use A Thermometer Every Time

London broil is lean, and the window between tender and firm is narrow. A thermometer turns guesswork into repeatable results.

Rest On A Board, Not A Cold Plate

A cold plate pulls heat fast. A board keeps the steak warm enough to finish gently while the juices settle.

Slice Across The Grain, No Exceptions

If you do only one thing from this whole page, do this. Thin slices across the grain change the bite more than any marinade ever will.