Marinate the Beef: In a mixing bowl, combine sliced flank steak with cornstarch, neutral oil, water, and baking soda. Let it marinate for 30 minutes to 1 hour in the refrigerator.

Prepare Vegetables: Wash and chop your bok choy, slice the bunashimeji mushrooms, and trim the sugar snap peas. Have all vegetables ready.

Make the Sauce: In a separate bowl, whisk together warm water, sesame oil, light soy sauce, dark soy sauce, oyster sauce, and sugar. Stir until dissolved.

Cook the Beef: Heat a wok or large skillet over high heat. Add neutral oil and marinated beef. Stir-fry about 30 seconds per side until 80% cooked.

Stir-fry Aromatics: In the same wok, add remaining oil and sauté minced ginger for a few seconds. Add garlic and stir for another 10 seconds.

Add Vegetables: Toss in the chopped mushrooms, sugar snap peas, and bok choy. Stir-fry for about 20 seconds until bok choy wilts.

Combine and Thicken: Return the beef to the wok with the sauce. Stir to combine, add cornstarch slurry, and toss for another minute.