Getting a London broil right in the oven is a classic cooking challenge. If you’ve ever wondered how long to cook a London broil in oven for the best results, you’re in the right place. This guide will walk you through the perfect temperature and time, along with all the tips you need to turn a tough cut into a tender, flavorful meal.
London broil isn’t actually a specific cut of meat. It’s a cooking method for lean, tougher steaks like top round or flank steak. The key is a good marinade, high heat, and most importantly, slicing it very thin against the grain. Doing this breaks up the muscle fibers, making each bite tender instead of chewy.
Let’s get your oven ready.
How Long To Cook A London Broil In Oven
This is the core question. The short answer is: at 400°F (204°C), a 1.5 to 2-pound London broil takes about 15 to 20 minutes for medium-rare, or 20 to 25 minutes for medium. Always use a meat thermometer for accuracy. You’re aiming for an internal temperature of 130-135°F (54-57°C) for medium-rare or 140-145°F (60-63°C) for medium.
Remember, cooking time varies based on your oven’s true temperature, the thickness of the meat, and whether you took it out of the fridge ahead of time. A thermometer is your best friend here.
Choosing the Right Cut of Meat
You can’t just grab any steak. For a proper London broil, look for these cuts at your butcher or grocery store:
- Top Round Steak: This is the most common and affordable choice. It’s lean and benefits greatly from marinating.
- Flank Steak: A bit more flavorful and tender than top round, but still needs the right preparation.
- Shoulder Steak: Another good option, though it can have a bit more connective tissue.
Avoid cuts that are already tender, like ribeye or strip steak. They’re expensive and don’t need this method. The whole point is to master the technique for tougher, budget-friendly meats.
The Essential Marinade
A marinade does two jobs: it adds flavor and starts to break down the tough muscle fibers. You should marinate your London broil for at least 4 hours, but overnight is even better.
Here’s a simple, effective marinade recipe:
- 1/2 cup soy sauce or tamari
- 1/4 cup olive oil
- 2 tablespoons Worcestershire sauce
- 2 tablespoons red wine vinegar or balsamic vinegar
- 4 cloves garlic, minced
- 1 teaspoon black pepper
- 1 teaspoon dried herbs (like thyme or rosemary)
Mix everything in a bowl or a zip-top bag. Add the steak, seal it, and let it sit in the refrigerator. Turn the bag occasionally so the marinade coats everything evenly.
Preparing Your Meat for the Oven
Preparation is simple but crucial. About 30 to 60 minutes before cooking, take the steak out of the fridge. Letting it come closer to room temperature helps it cook more evenly. Pat it completely dry with paper towels. This is important! A dry surface will sear and brown beautifully. A wet steak will steam.
Lightly brush the steak with a little oil and season generously with salt and pepper just before it goes in the oven. The marinade has flavor, but a final seasoning on the surface makes a big difference.
Step-by-Step Oven Cooking Instructions
Follow these steps for a perfectly cooked London broil.
Step 1: Preheat and Prepare Your Pan
Preheat your oven to 400°F (204°C). Place a heavy oven-safe skillet (cast iron is perfect) or a baking sheet with a wire rack on the middle rack while the oven heats. Starting with a hot pan gives you a better sear.
Step 2: Sear the Steak (Optional but Recommended)
Carefully remove the hot skillet from the oven using oven mitts. Place it on the stovetop over medium-high heat. Add a small amount of high-heat oil (like canola or avocado oil). Sear the steak for 2-3 minutes per side until a nice brown crust forms. This step adds incredible flavor.
Step 3: Cook to the Right Temperature
If you seared in the skillet, just put the whole skillet back in the oven. If you used a baking sheet, transfer the steak to the wire rack. Roast until the internal temperature reaches your desired doneness. Check it early and often with your meat thermometer.
- Medium-Rare: 130-135°F (54-57°C) – About 15-20 mins total.
- Medium: 140-145°F (60-63°C) – About 20-25 mins total.
We do not recommend cooking past medium, as the meat can become tough and dry.
Step 4: The Most Important Step – Resting
Once the steak hits temperature, take it out and place it on a clean cutting board. Loosely tent it with aluminum foil. Let it rest for a full 10 minutes. This allows the juices, which have been driven to the center by the heat, to redistribute throughout the entire steak. If you skip this, the juices will run out on the board when you slice it.
Step 5: Slicing Against the Grain
Look closely at the meat. You will see lines running in one direction—this is the “grain.” Using a very sharp knife, slice the steak thinly, perpendicular (across) these lines. Slicing against the grain shortens the long muscle fibers, making the meat much easier to chew and giving it a tender texture.
Alternative Cooking Temperatures and Times
While 400°F is the standard for a reason, you can use other methods.
- High Heat (450°F / 232°C): Cook for 10-15 minutes. This gives a great crust but requires careful monitoring to avoid overcooking.
- Broiler Method: Place the steak on a broiler pan about 4 inches from the heat. Broil for 6-8 minutes per side, watching closely to prevent burning.
- Low and Slow (Not Recommended): London broil is too lean for traditional low-temperature roasting. It will dry out before it becomes tender. Stick with higher heat.
How to Tell When Your London Broil is Done
Never guess. The finger test is unreliable for this cut. The only sure way is to use an instant-read meat thermometer. Insert it into the thickest part of the steak, avoiding any fat or bone. Trust the numbers, not the clock.
Common Mistakes to Avoid
Here’s how to steer clear of problems:
- Skipping the Marinade: The meat will be less flavorful and more tough.
- Not Drying the Steak: A wet surface prevents browning.
- Overcooking: This is the biggest mistake. Use a thermometer and pull it at the right temp.
- Skipping the Rest: You’ll lose all those good juices.
- Slicing With the Grain: This results in a long, stringy, and chewy piece of meat.
- Using a Dull Knife: A dull knife will tear the meat instead of slicing it cleanly.
Serving Suggestions
Your perfectly cooked London broil is the star. Serve it with sides that complement its rich flavor.
- Classic: Mashed potatoes and roasted green beans or asparagus.
- Light: A big, crisp garden salad with a vinaigrette.
- Hearty: Garlic butter mushrooms and onions.
The thin slices are also fantastic in sandwiches, on top of salads, or in fajitas the next day. Leftovers keep well in the fridge for 3-4 days.
Storing and Reheating Leftovers
Store leftover sliced meat in an airtight container in the refrigerator. To reheat without drying it out, use gentle methods.
- Skillet: Warm a little broth or water in a skillet, add the slices, and cover for just a minute until heated through.
- Oven: Place slices in a baking dish with a bit of broth, cover with foil, and warm at 275°F (135°C) for 10-15 minutes.
Avoid the microwave if you can, as it can make the meat rubbery.
FAQ Section
What is the best temperature to cook London broil?
The best temperature is 400°F (204°C). This high heat cooks the steak quickly, creating a nice exterior while keeping the inside juicy. It’s the most reliable method for home cooks.
Can I cook a London broil without marinating it?
You can, but we don’t recommend it. The marinade is crucial for adding flavor and tenderizing this lean cut. A quick 30-minute soak is better than nothing, but for the best results, plan ahead and marinate for several hours.
Why is my London broil always tough?
There are three likely reasons: you overcooked it, you didn’t slice it thin enough against the grain, or you didn’t let it rest before slicing. Fixing these three steps will solve most toughness problems.
How do I slice London broil correctly?
First, identify the direction of the muscle fibers (the grain). Then, using a very sharp knife, cut thin slices perpendicular (at a 90-degree angle) to that grain. This makes the pieces tender.
Can I use a different cut for London broil?
Yes, the method works for other lean, tough cuts. Flank steak and top round are the top choices. Shoulder steak can also work well. Avoid already tender cuts like filet mignon.
What internal temperature should I aim for?
For medium-rare, aim for 130-135°F (54-57°C). For medium, aim for 140-145°F (60-63°C). Always remove the meat from the oven about 5 degrees before it hits your target, as the temperature will continue to rise while resting (this is called carryover cooking).
Mastering the London broil is a valuable kitchen skill. It turns an economical piece of meat into a impressive and satisfying dinner. By following these steps—marinating, cooking at the right temperature, resting, and slicing correctly—you’ll get a fantastic result everytime. Remember, your meat thermometer is the most important tool in this process. Now you have all the knowledge you need to make a perfect London broil in your own oven.