Mongolian Beef

Ingredients

• 1 pound Flank Steak (trimmed, cut into 1‑inch cubes after slicing against the grain)
• 1/2 teaspoon Baking Soda (helps tenderize the beef)
• 3 tablespoons Cornstarch (2 tbsp for the marinade, 1 tbsp for the sauce slurry)
• 1/2 teaspoon Salt (seasoning for the marinade)
• 2 tablespoons Water (for the marinade)
• 3 tablespoons Vegetable Oil (2 tbsp for searing, 1 tsp in the marinade)
• 4 cloves Garlic (minced (thin slices, not pureed))
• 1 tablespoon Fresh Ginger (peeled and thinly sliced)
• 1 Red Bell Pepper (seeded, cut into 1‑inch dice)
• 1 Green Bell Pepper (seeded, cut into 1‑inch dice)
• 1 medium Onion (peeled and diced 1‑inch pieces)
• 4 stalks Scallions (whites sliced thin, greens cut for garnish)
• 3 tablespoons Oyster Sauce (main savory component)
• 1 tablespoon Hoisin Sauce (adds sweetness and sheen)
• 2 tablespoons Soy Sauce (provides salty backbone)
• 1 teaspoon Rice Vinegar (adds bright acidity)
• 2 Dried Red Chilies (optional, for a hint of heat)
• 1 tablespoon cornstarch + 2 tablespoons water Cornstarch Slurry (mix together just before adding to sauce)

Instructions

1. Make the Marinade

   In a mixing bowl combine 1/2 tsp baking soda, 2 tbsp cornstarch, 1/2 tsp salt, 2 tbsp water and 1 tsp vegetable oil. Stir until smooth.

   Time: PT5M

2. Slice the Beef

   Trim the flank steak, cut it into 1‑inch strips with the grain, then turn and cut across the grain into 1‑inch cubes.

   Time: PT5M

3. Marinate the Beef

   Add the beef cubes to the bowl, massage the mixture so every piece is coated. Cover tightly and refrigerate.

   Time: PT5M

4. Marination Rest

   Let the beef sit in the fridge for at least 2‑4 hours, preferably 3 hours, to become super‑tender.

   Time: PT3H30M

5. Prep the Vegetables

   Mince garlic (thin slices then chop), thinly slice ginger, dice both bell peppers and the onion into 1‑inch pieces, slice scallion whites 1‑inch strips and set greens aside for garnish.

   Time: PT15M

6. Prepare the Sauce

   In a small bowl whisk together 3 tbsp oyster sauce, 1 tbsp hoisin sauce, 2 tbsp soy sauce, 1 tsp rice vinegar, dried chilies (if using) and the cornstarch slurry (1 tbsp cornstarch + 2 tbsp water).

   Time: PT5M

7. Heat the Wok

   Place the wok over high heat until it begins to smoke. If you smell a faint plastic odor, scrub the interior with a tablespoon of kosher salt and a paper towel, then rinse.

   Time: PT2M

8. Sear the Beef

   Add 2 tbsp vegetable oil, swirl, then add the marinated beef in a single layer. Let it sit untouched for 2 minutes, then stir‑fry until the exterior is browned and the interior is medium‑rare (about 3‑4 minutes total).

   Time: PT4M

9. Drain Excess Oil

   Transfer the beef to a plate lined with paper towels and discard excess oil from the wok.

   Time: PT1M

10. Aromatics

    Add the minced garlic and sliced ginger to the hot wok. Stir‑fry for about 30 seconds until fragrant.

    Time: PT1M

11. Cook Vegetables

    Add the diced onion and bell peppers. Stir‑fry 4‑5 minutes until the edges are lightly browned but the pieces remain crisp‑tender.

    Time: PT5M

12. Combine Beef and Sauce

    Return the beef (and any juices) to the wok, add the sliced scallion whites, then pour in the prepared sauce. Bring to a gentle boil, stirring constantly, until the sauce thickens and coats everything (about 2‑3 minutes).

    Time: PT3M

13. Finish and Garnish

    Turn off the heat, toss in the scallion greens for color, give a quick stir, and serve immediately.

    Time: PT1M

Nutrition Facts

Calories

350

Protein

25g

Carbohydrates

20g

Fat

15g

Fiber

3g

Ingredient Substitutions

• Instead of Flank Steak: Top Sirloin, Flat Iron Steak
• Instead of Cornstarch: Potato starch
• Instead of Salt: Kosher salt
• Instead of Vegetable Oil: Canola oil, Peanut oil
• Instead of Garlic: Garlic paste
• Instead of Fresh Ginger: Ground ginger (use less)
• Instead of Red Bell Pepper: Yellow or green bell pepper
• Instead of Green Bell Pepper: Red or yellow bell pepper
• Instead of Onion: Sweet onion, shallots
• Instead of Scallions: Green onions
• Instead of Oyster Sauce: Mushroom soy sauce
• Instead of Hoisin Sauce: Additional soy sauce + honey
• Instead of Soy Sauce: Tamari (gluten‑free)
• Instead of Rice Vinegar: Apple cider vinegar
• Instead of Dried Red Chilies: Crushed red pepper flakes
• Instead of Cornstarch Slurry: Potato starch slurry

Equipment Needed

• Wok
• Chef's Knife
• Cutting Board
• Mixing Bowl
• Measuring Spoons
• Small Bowl (for slurry)
• Spatula or Wok Ladle
• Paper Towels (optional)

Critical Steps — Do Not Skip

• Make the Marinade
• Slice the Beef
• Marinate the Beef
• Sear the Beef
• Combine Beef and Sauce

Chef Tips from the Video

• Pat the marinated beef dry with paper towels before searing for a better crust.
• Use a high‑smoke‑point oil (peanut or grapeseed) if you prefer an even higher sear temperature.
• Add a splash of water to deglaze the wok after the vegetables are cooked, then return the beef for extra flavor.

Troubleshooting

Storage

Refrigerator: Store leftovers in an airtight container for up to 3 days.

Freezer: Freeze cooked beef and sauce separately for up to 1 month; reheat gently.

Room temperature: Do not store at room temperature for more than 2 hours.

Make-Ahead Tips

• Marinate the beef up to 24 hours in advance; keep it covered in the fridge.
• Dice all vegetables and store them in sealed bags; they stay fresh for a day.
• Prepare the sauce and slurry ahead; give the slurry a quick stir before using.