Sliced London Broil Recipe

Marinate the beef

In a shallow dish or resealable bag, whisk together olive oil, soy sauce, Worcestershire sauce, red wine vinegar, brown sugar, minced garlic, dried oregano, black pepper, and kosher salt. Add the 1 lb London broil and turn to coat evenly. Marinate in the refrigerator for at least 1 hour and up to 8 hours. Remove from refrigerator 30 minutes before cooking to come to near room temperature.

Preheat and sear

Preheat oven to 425°F (220°C). Heat a heavy ovenproof skillet (cast iron preferred) over high heat until very hot. Add the vegetable oil and, when it shimmers, place the marinated London broil in the skillet. Sear without moving for 2–3 minutes until a deep brown crust forms. Flip and sear the other side 2 minutes.

Roast to temperature

Add 1 tablespoon butter to the pan if using, and tilt the pan to baste the top briefly. Transfer the skillet to the preheated oven and roast until internal temperature reaches 125–130°F (52–54°C) for medium-rare, about 6–10 minutes depending on thickness. For medium, target 135°F (57°C). Use an instant-read thermometer inserted into the thickest part.

Rest and slice

Remove the steak to a cutting board and tent loosely with foil. Rest for 10–12 minutes to allow juices to redistribute. Slice the beef thinly across the grain into 1/8–1/4 inch slices for maximum tenderness.

Make au jus

While the steak rests, place the skillet used to sear the beef over medium heat. Add the minced shallot and sauté 30–45 seconds in the pan drippings until softened. Pour in the red wine (if using) to deglaze, scraping up browned bits from the bottom with a wooden spoon. Reduce for 1 minute, then add beef broth and fresh thyme. Bring to a gentle simmer and let reduce 4–6 minutes until slightly concentrated. Whisk in 1 tablespoon butter off heat for sheen, season with salt and pepper to taste. Strain if you prefer a smooth jus. Serve warm alongside the sliced London broil.

Cook mushrooms

In a medium skillet over medium-high heat, melt 2 tablespoons butter. Add the sliced mushrooms and spread into an even layer. Cook, undisturbed, 3–4 minutes until browned, then stir and cook another 2 minutes until nicely golden.

Finish sauce

Add the minced shallot (or small onion) and garlic and sauté 30–45 seconds until fragrant. Pour in 1/2 cup beef broth and scrape up browned bits, simmer 2–3 minutes to reduce slightly. Stir in heavy cream and Dijon mustard and simmer 1–2 minutes until slightly thickened. Season with salt and pepper and stir in chopped parsley. Remove from heat and keep warm. If you want a silkier sauce, blend briefly or strain for a smoother texture.

Arrange sliced London broil on a warm platter. Spoon either the warm au jus or mushroom sauce over the meat or serve the sauce on the side. Garnish with chopped parsley. Serve immediately with desired sides (mashed potatoes, roasted vegetables or a simple salad).