Marinating London broil overnight tenderizes the meat, making it perfect for quick, high-heat grilling. If you have ever wondered how to cook a london broil that is juicy and not tough, you are in the right place. This cut of beef, usually from the top round or flank, can be tricky because it is lean. But with the right method, you get a flavorful, tender steak every time. Let us walk through the entire process step by step, from choosing the meat to slicing it correctly.
London broil is not actually a specific cut of meat. It is a cooking method and a dish name. Most grocery stores label a large, flat cut as “London broil,” often from the top round. Because this meat is lean, it needs a good marinade and careful cooking. Overcooking makes it tough and chewy. The secret is to cook it quickly over high heat to medium-rare, then slice it thinly against the grain.
What Is London Broil Exactly?
First, understand what you are buying. London broil is typically a beef round steak, about 1 to 2 inches thick. It can also be flank steak or sirloin tip. The name comes from a recipe, not the cow. The meat is lean with long muscle fibers. That is why marinating and thin slicing are so important. Do not confuse it with a tender cut like ribeye or sirloin. It requires a bit more attention.
When you see “London broil” at the store, it is usually a top round or bottom round steak. These cuts are affordable but need proper handling. The marinade helps break down the fibers, and high heat sears the outside while keeping the inside pink. Aim for medium-rare, about 130-135°F internal temperature. Anything beyond medium-well will be dry and tough.
Choosing The Right Cut
Look for a piece that is uniform in thickness. This ensures even cooking. A 1.5-inch thick steak is ideal. If it is too thin, it cooks too fast and dries out. If it is too thick, the outside may burn before the inside is done. Check for good marbling, even though this cut is lean. A little fat running through the meat adds flavor. Avoid pieces with large chunks of fat or gristle.
Fresh meat is best, but frozen works too. Thaw it completely in the fridge before marinating. Never use a microwave to thaw London broil, as it can start cooking the edges unevenly. Plan ahead: thawing takes about 24 hours in the refrigerator.
How To Cook A London Broil
Now we get to the main event. This method works for grilling, broiling, or pan-searing. The key is high heat and short cooking time. Follow these steps for a perfect result every time.
Step 1: Prepare The Marinade
A good marinade does two things: adds flavor and tenderizes. Use an acidic ingredient like vinegar, citrus juice, or wine. Oil helps carry flavors and prevents sticking. Add herbs, garlic, soy sauce, or Worcestershire for depth. Here is a simple but effective recipe:
- 1/4 cup olive oil
- 1/4 cup soy sauce
- 2 tablespoons red wine vinegar
- 2 cloves garlic, minced
- 1 tablespoon brown sugar
- 1 teaspoon black pepper
- 1 teaspoon dried rosemary or thyme
Mix all ingredients in a bowl or zip-top bag. Place the London broil in the bag, seal it, and massage the marinade into the meat. Refrigerate for at least 4 hours, but overnight is best. The longer it marinates, the more tender and flavorful it becomes. Do not exceed 24 hours, as the acid can start to break down the meat too much, making it mushy.
Step 2: Bring To Room Temperature
About 30 minutes before cooking, take the meat out of the fridge. Remove it from the marinade and let it sit on a plate. Pat it dry with paper towels. This step is crucial. A dry surface sears better and creates a nice crust. If the meat is cold, it will cook unevenly. Room temperature meat cooks more consistently from edge to center.
Discard the leftover marinade. Do not reuse it for basting or sauce unless you boil it first to kill bacteria. You can make a separate sauce if you like, but for simplicity, we will skip that here.
Step 3: Preheat Your Cooking Surface
Whether you use a grill, broiler, or cast-iron skillet, get it very hot. For grilling, preheat to high heat, around 450-500°F. For broiling, set your oven to high broil and let the element heat for 10 minutes. For pan-searing, heat a heavy skillet over medium-high heat until it smokes slightly. Add a little oil with a high smoke point, like avocado or canola oil.
A hot surface sears the meat quickly, locking in juices. If the heat is too low, the meat will steam and become tough. You want a good sizzle when the steak hits the pan or grill.
Step 4: Cook The London Broil
Place the steak on the hot surface. Do not move it for 4-5 minutes. This allows a deep brown crust to form. Flip it once and cook the other side for another 4-5 minutes. For a 1.5-inch thick steak, total cooking time is about 8-10 minutes for medium-rare. Use an instant-read thermometer to check doneness. Insert it into the thickest part. Target 130-135°F for medium-rare, 140°F for medium.
If you like it more done, cook a bit longer, but be careful. Beyond 150°F, the meat becomes tough and dry. Remember, the temperature will rise about 5°F while resting, so pull it off a few degrees early.
Step 5: Rest The Meat
This step is non-negotiable. Transfer the cooked London broil to a cutting board and tent loosely with foil. Let it rest for 5-10 minutes. Resting allows the juices to redistribute throughout the meat. If you cut it right away, the juices run out, leaving dry meat. The rest time also lets the internal temperature stabilize.
While it rests, you can prepare a quick side dish or sauce. But do not skip this. It makes a huge difference in tenderness.
Step 6: Slice Against The Grain
This is the most important step for tenderness. Look at the meat and find the direction of the muscle fibers. They run in long lines. You want to slice perpendicular to those lines, not parallel. Cutting against the grain shortens the fibers, making each bite easier to chew. Slice thin, about 1/4-inch thick pieces. A sharp knife helps.
If you slice with the grain, the meat will be stringy and tough, no matter how well you cooked it. Take your time here. Angle the knife slightly for wider slices if you prefer. Serve immediately.
Alternative Cooking Methods
Grilling is classic, but you can also cook London broil in the oven or on the stove. Each method works well with the same principles: high heat, short time, and resting.
Broiling In The Oven
Set your oven rack about 4-6 inches from the broiler element. Preheat on high. Place the marinated and dried steak on a broiler pan or a wire rack set over a baking sheet. Broil for 5-6 minutes per side for medium-rare. Watch it closely, as broilers vary. The surface should be nicely charred. Check temperature and rest as usual.
Pan-Searing On The Stove
Use a heavy skillet like cast iron. Heat it over high heat until smoking. Add a tablespoon of oil. Sear the steak for 4-5 minutes per side. If the steak is thick, you can finish it in a preheated oven at 400°F for a few minutes. Use a thermometer to check doneness. This method gives a great crust.
Sous Vide Option
For ultimate control, try sous vide. Season the meat, seal it in a bag, and cook in a water bath at 130°F for 2-4 hours. Then sear it in a hot pan for 1 minute per side. This guarantees perfect doneness edge to edge. It is a bit more work but worth it for special occasions.
Common Mistakes To Avoid
Even with good instructions, things can go wrong. Here are pitfalls to watch out for:
- Not marinating long enough: Less than 4 hours gives little flavor or tenderizing.
- Skipping the rest: Cutting too soon loses all the juices.
- Overcooking: London broil is lean; well-done is a disaster.
- Slicing with the grain: This makes the meat chewy, no matter how tender it is.
- Using low heat: You need high heat for a good sear and quick cooking.
Avoid these, and you will have a great meal. Also, do not poke the meat with a fork while cooking. Use tongs to flip it. Poking releases juices.
What To Serve With London Broil
This steak pairs well with simple sides. Roasted vegetables like asparagus, broccoli, or carrots work great. A baked potato or mashed potatoes are classic. A fresh green salad with a vinaigrette cuts the richness. You can also serve it with a chimichurri sauce or a mushroom gravy. The key is to keep sides simple so the beef shines.
Leftover London broil is excellent in sandwiches or salads. Slice it thin and use it cold or gently reheated. It also works well in stir-fries or on top of a grain bowl. Just do not reheat it in the microwave, as it will toughen. Warm it gently in a pan with a little broth or sauce.
Frequently Asked Questions
Can I Cook London Broil Without Marinating?
Yes, but it will be less tender and flavorful. The marinade helps break down the muscle fibers. If you skip it, consider using a tenderizing mallet or a dry brine with salt for a few hours. Still cook to medium-rare and slice thin.
How Do I Know When London Broil Is Done?
Use an instant-read thermometer. For medium-rare, aim for 130-135°F. For medium, 140°F. The meat will continue to cook while resting, so remove it a few degrees early. Color is not reliable; always use a thermometer.
Why Is My London Broil Tough?
Most likely overcooked or sliced incorrectly. If cooked beyond medium, the lean meat becomes tough. Also, slicing with the grain instead of against it makes it chewy. Next time, cook to medium-rare and slice against the grain.
Can I Freeze Cooked London Broil?
Yes, slice it first and store in an airtight container or freezer bag. It keeps for up to 3 months. Thaw in the fridge overnight and reheat gently. Use it in sandwiches or salads to avoid drying it out.
What Is The Best Marinade For London Broil?
Any marinade with acid, oil, and flavor works. A classic mix is soy sauce, olive oil, garlic, and vinegar. You can also use balsamic, citrus, or red wine. Add herbs like rosemary or thyme. Marinate overnight for best results.
Final Tips For Success
Remember, cooking London broil is about technique, not luck. Marinate overnight, cook hot and fast, rest well, and slice thin against the grain. That is the whole secret. Do not be afraid to experiment with different marinades or cooking methods. Each time you make it, you will get better.
If you follow these steps, you will have a tender, flavorful steak that rivals more expensive cuts. It is a great weeknight dinner that feels special. Serve it with your favorite sides and enjoy. The key is practice. Soon, you will be able to cook it perfectly every time.
Now you know exactly how to cook a london broil. Go ahead and try it tonight. Your family and friends will be impressed. And remember, the most important part is slicing against the grain. Do not skip that step. Happy cooking.