Perfect Oven London Broil: Step-by-Step Cooking Guide

The perfect oven-cooked London broil requires preheating to 400°F, cooking for 15-20 minutes until reaching 130-135°F internal temperature for medium-rare, then resting 10 minutes before slicing against the grain. This method delivers tender, flavorful results every time with proper temperature control and resting technique.

Why This Oven Method Works for London Broil

London broil isn't actually a specific cut of beef but rather a cooking method traditionally applied to tougher, lean cuts like top round or flank steak. When cooked properly in the oven, these affordable cuts transform into restaurant-quality meals. The high-heat oven method creates a flavorful crust while maintaining tenderness throughout the meat.

According to the USDA Food Safety and Inspection Service, beef steaks should reach a minimum internal temperature of 145°F with a 3-minute rest period for safety. However, for premium cuts like properly prepared London broil, many chefs recommend removing from heat at 130-135°F for medium-rare, as the temperature will continue rising during resting.

Essential Preparation Steps

Your London broil's success begins long before it hits the oven. Proper preparation makes all the difference between tough and tender results.

Selecting and Preparing Your Cut

Look for a 1.5-2 inch thick top round or flank steak with even marbling. The National Cattlemen's Beef Association confirms that London broil traditionally refers to top round but can include flank steak, sirloin tip, or chuck shoulder.

Before cooking, bring your meat to room temperature (about 45-60 minutes out of the refrigerator). This ensures even cooking. Pat the surface completely dry with paper towels - moisture is the enemy of proper browning.

Cooking Stage	Temperature	Target Internal Temp	Resting Time
Rare	400°F	120-125°F	8-10 minutes
Medium-rare	400°F	130-135°F	10 minutes
Medium	400°F	140-145°F	10-12 minutes

Marinating for Maximum Flavor

While not mandatory, marinating significantly improves flavor and tenderness. Create a simple marinade with:

• 1/3 cup olive oil
• 3 tablespoons soy sauce
• 2 tablespoons Worcestershire sauce
• 3 minced garlic cloves
• 1 tablespoon fresh rosemary, chopped
• 1 teaspoon black pepper

Marinate for 4-12 hours in the refrigerator, but never more than 24 hours as the acid can begin to break down the meat too much.

The Oven Cooking Process: Step by Step

Many home cooks make critical errors during the cooking phase that lead to tough, dry results. Follow these precise steps for perfect oven-cooked London broil.

Proper Oven Setup

Preheat your oven to 400°F at least 20 minutes before cooking. Position the oven rack in the upper third of the oven. Place a wire rack inside a rimmed baking sheet to allow air circulation around the meat.

The American Meat Science Association emphasizes that "resting allows the juices to be reabsorbed into the fibers of the meat. If you skip resting, you will lose more juices when you cut it, and your meat will be dry." This principle applies equally to the cooking phase - proper air circulation ensures even cooking.

Cooking Time and Temperature Control

Place the London broil on the prepared rack and insert an oven-safe meat thermometer into the thickest part. Cook for 15-20 minutes for medium-rare (130-135°F), 20-25 minutes for medium (140-145°F). Cooking time varies based on thickness and oven accuracy.

For best results, use the reverse-sear method for thicker cuts (over 2 inches): cook at 275°F until reaching 115°F internally, then increase heat to 450°F for 5-7 minutes to develop a crust. The Culinary Institute of America recommends this technique for thicker cuts to prevent the exterior from overcooking before the interior reaches proper temperature.

Critical Resting and Slicing Techniques

This is where most home cooks fail with London broil. Proper resting and slicing transforms your cooked meat from good to exceptional.

The Science of Resting

After removing from the oven, tent loosely with foil and rest for 10-12 minutes. During this time, the internal temperature will rise 5-10 degrees (carryover cooking), and the muscle fibers will relax, redistributing juices throughout the meat.

Slicing Against the Grain

Identify the direction of the muscle fibers (the grain) and slice perpendicular to them. For London broil, this typically means cutting across the width of the steak in 1/4 inch slices. Slicing against the grain shortens the muscle fibers, making each bite more tender.

Troubleshooting Common London Broil Problems

Even with careful preparation, issues can arise. Here's how to handle them:

Problem: Tough, Chewy Results

Solution: This usually happens from either under-marinating, overcooking, or improper slicing. Always slice against the grain, ensure proper internal temperature, and consider extending marinating time for future attempts.

Problem: Uneven Cooking

Solution: This occurs when the meat isn't at room temperature before cooking or when the oven temperature is inconsistent. Always bring meat to room temperature and use an oven thermometer to verify your oven's accuracy.

Serving Suggestions for Perfect Results

Serve your perfectly cooked London broil with these complementary sides:

• Roasted garlic mashed potatoes
• Grilled asparagus or green beans
• Simple pan sauce made from drippings

Leftovers make excellent steak sandwiches or salad toppings when sliced thin and reheated gently.

What's the best oven temperature for cooking London broil?

The optimal oven temperature for London broil is 400°F. This high heat creates a flavorful crust while cooking the interior to perfect doneness. For thicker cuts over 2 inches, use the reverse-sear method: start at 275°F until 115°F internally, then finish at 450°F for 5-7 minutes.

How long should London broil rest before slicing?

London broil should rest for 10-12 minutes after cooking. This resting period allows the muscle fibers to relax and redistribute juices throughout the meat. Cutting too soon causes precious juices to escape, resulting in dry, tough steak. Tent loosely with foil during resting to maintain temperature.

Why is my oven-cooked London broil always tough?

London broil becomes tough primarily from three mistakes: overcooking, improper slicing, or skipping the resting period. Always cook to 130-135°F for medium-rare, rest 10+ minutes, and slice against the grain in 1/4 inch slices. Marinating for 4-12 hours also helps tenderize this lean cut.

Can I cook London broil without a meat thermometer?

While a meat thermometer is strongly recommended for perfect results, you can estimate doneness by touch. For medium-rare, the steak should feel like the fleshy part of your palm below the thumb when you touch your thumb to your middle finger. However, this method is less accurate than using a thermometer, especially for thicker cuts.