Mongolian Beef Delight

Mongolian beef is a stir-fry of tender beef strips coated in a glossy, slightly sweet and savory sauce with a hint of heat. The beef stays tender because it’s cut thin, cooked fast over high heat, and never crowded in the pan. Served over rice with scallions, it comes together in under thirty minutes.

Ingredients for Mongolian Beef Delight

Beef flank steak cooks quickly when sliced thin against the grain. Soy sauce and brown sugar build the savory-sweet base of the sauce, while ginger and garlic add depth and warmth. Cornstarch thickens the sauce to a gloss and helps the beef brown. Vegetable oil gets hot enough to sear without smoking, and beef broth loosens the browned bits stuck to the pan. Rice vinegar brightens the sauce with tang, red pepper flakes bring heat, and scallions finish the dish with fresh bite.

Why This Mongolian Beef Delight Works

Flank steak is lean and flavorful, but it toughens fast if cooked past medium. Cutting it thin and cooking it in a screaming-hot pan for just a minute or two keeps it tender. The cornstarch does double duty: it seasons the meat and helps it brown deeply, creating flavor before the sauce goes in.

The sauce comes together in the same pan after the beef rests. The beef broth hits the hot pan and lifts all the browned bits, which dissolve into the liquid and add richness. Cornstarch slurry thickens it to a glaze that clings to the beef instead of pooling on the plate.

Mistakes To Avoid

Overcooked beef turns dry and chewy. If you cook it all at once in a crowded pan, the steam prevents browning and the meat stews instead of searing. Cook in two batches and pull the beef out as soon as it reaches 130°F (54°C) inside, checked with an instant-read thermometer at the thickest part.

Lumpy sauce ruins the dish. Cornstarch clumps if you dump it straight into hot liquid. Whisk it with cold broth first so it dissolves smoothly, then pour it in slowly while stirring. The sauce will thicken in seconds.

Thin, watery sauce means the cornstarch was not whisked in properly or the heat was too low when you added it. Make sure the pan is hot and the liquid is simmering when the cornstarch slurry goes in. Stir constantly for a full minute so it cooks through.

Tough or stringy beef comes from cutting with the grain instead of against it. Look at the lines of muscle running through the raw meat and cut perpendicular to them. This breaks the fibers and makes each bite tender.

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Ingredients

• 1 1/2 pounds beef flank steak
• 3 tablespoons cornstarch
• 1/2 teaspoon salt
• 1/4 teaspoon black pepper
• 3 tablespoons vegetable oil
• 3 cloves garlic, minced
• 1 tablespoon grated ginger
• 1/2 cup soy sauce
• 1/4 cup brown sugar
• 1/2 cup beef broth
• 2 tablespoons rice vinegar
• 1/4 teaspoon red pepper flakes
• 3 scallions, sliced into 1-inch pieces

Step-by-step Instructions

1. Slice the beef flank steak against the grain into 1/4-inch strips. Pat dry with paper towels.
2. Mix cornstarch, salt, and black pepper in a bowl. Toss the beef strips with the cornstarch mixture until coated.
3. Heat 1 1/2 tablespoons oil in a wok or large skillet over high heat until it shimmers, about 1 minute. Add half the beef in a single layer and cook without moving for 1 minute until browned on one side, then toss and cook 30 seconds more until it reaches 130°F (54°C) inside. Transfer to a plate.
4. Add the remaining 1 1/2 tablespoons oil to the pan and repeat with the second batch of beef. Transfer to the plate with the first batch.
5. Reduce heat to medium. Add garlic and ginger to the pan and cook, stirring, for 30 seconds until fragrant.
6. Whisk soy sauce, brown sugar, beef broth, and rice vinegar in a small bowl. Pour slowly into the pan while stirring constantly. Add red pepper flakes and simmer for 1 minute, stirring often, until the sauce thickens and coats the back of a spoon.
7. Return all the beef and any resting juices to the pan. Toss gently for 30 seconds to coat with sauce and heat through. Remove from heat.
8. Stir in scallions just before serving.