In a large bowl, combine thinly sliced flank steak with cornstarch, neutral oil, a pinch of baking soda, and water. Mix well and let marinate for at least 30 minutes.

Chop the bok choy, mushrooms, and sugar snap peas into bite-sized pieces and set aside.

In a medium bowl, whisk together water or beef stock, sesame oil, light and dark soy sauces, and oyster sauce until combined.

Preheat your wok over high heat until it begins to smoke lightly, about 2-3 minutes. Add neutral oil.

Add the marinated beef to the wok and sear for 30 seconds without stirring; then flip and sear for another 30 seconds. Remove and set aside.

Pour in more neutral oil, followed by minced garlic and ginger. Sauté for about 15 seconds until fragrant.

Add the mushrooms, stir-frying for 15 seconds until soft. Add bok choy and sugar snap peas, cooking for another 20 seconds.

Return the beef to the wok and pour the sauce mixture over. Stir quickly to coat beef and vegetables, cooking for another 30 seconds.

Gradually add the cornstarch slurry to thicken the sauce while stirring, cooking for another 20 seconds.

Serve immediately, ideally over steamed rice or alongside noodles.