Mongolian Beef Recipe

Slice

Trim any excess fat from the flank steak. Freeze the steak for 20–30 minutes until slightly firm to make slicing easier. Slice thinly across the grain into 1/8–1/4 inch strips.

Marinate

Place the beef strips in a bowl. Add 2 tablespoons soy sauce, 1/2 teaspoon baking soda, 1/4 teaspoon salt, and 1/4 teaspoon black pepper. Toss to coat and let rest 10–15 minutes at room temperature. The baking soda tenderizes and helps the cornstarch adhere.

Coat with cornstarch

After resting, add 1/2 cup cornstarch to the beef a little at a time and toss until each strip is lightly and evenly coated. Shake off any excess cornstarch.

Heat a large skillet or wok over high heat until very hot. Add 2 tablespoons vegetable oil and swirl to coat. Working in a single layer (in batches if necessary to avoid steaming), add beef strips and sear without overcrowding for 1–2 minutes per side until the exterior is crisp and browned. Remove seared beef to a plate and repeat with remaining beef, adding more oil if needed.

While searing the beef, whisk together 1/2 cup low-sodium soy sauce, 1/4 cup water, 1/4 cup packed brown sugar, 1 tablespoon hoisin, 1 tablespoon rice vinegar, and 1/2 teaspoon sesame oil in a bowl until sugar dissolves. In a small cup, mix 1 teaspoon cornstarch with 1 tablespoon cold water to make a slurry and set aside.

After all beef is seared and removed, discard excess oil leaving about 1 tablespoon in the pan. Reduce heat to medium-high, add 2 tablespoons neutral oil if pan is dry. Add minced garlic and minced ginger and sauté for 20–30 seconds until fragrant (do not burn). If using, add 1/4 tsp red pepper flakes and stir briefly.

Pour the sauce mixture into the pan and bring to a gentle boil. Stir and cook 1–2 minutes to meld flavors. Stir the cornstarch slurry again and slowly add to the bubbling sauce while stirring. Cook for 30–60 seconds until sauce thickens to a glossy, coat-able consistency. Taste and adjust: add up to 1/2 tablespoon water if too salty or a pinch more brown sugar if not sweet enough.

Return the seared beef and any accumulated juices to the pan. Toss well to coat every piece in the sauce and cook together for 1 minute so beef finishes cooking and sauce clings. Stir in most of the sliced green onions (reserve some for garnish).

Remove from heat. Drizzle 1/2 teaspoon sesame oil over the beef and toss. Transfer to a serving plate. Garnish with remaining green onions and 1 teaspoon sesame seeds if using.

Serve immediately with steamed white rice or fried rice and steamed vegetables.