Begin by slicing the flank steak thinly against the grain for tenderness. In a mixing bowl, combine the beef with cornstarch, a splash of neutral oil, warm water, and baking soda. Toss the steak until evenly coated and let it rest for at least 30 minutes.

While the beef marinates, wash and prep your vegetables. Cut the bok choy into bite-sized pieces, trimming the base, and slice the bunashimeji mushrooms if they’re whole. For added crunch, trim the ends of sugar snap peas.

In a separate bowl, whisk together warm water or beef stock with sesame oil, light and dark soy sauces, oyster sauce, and a dash of sugar. Stir until the sugar dissolves completely.

Heat your wok over medium-high heat until it begins to lightly smoke. Pour in 2 tablespoons of neutral oil, allowing it to heat up. Add the marinated beef in a single layer. Sear for about 30 seconds on each side until browned but not fully cooked through. Remove the beef and set aside.

In the same wok, add more oil if necessary, then toss in finely minced garlic and ginger. Stir-fry for about 15 seconds until fragrant. Add bunashimeji mushrooms and stir-fry for another minute.

Add the prepared bok choy and sugar snap peas. Stir-fry together for about 20 seconds until the bok choy starts to wilt slightly.

Add the beef back to the wok along with the prepared sauce mixture. Stir everything together gently, keeping the heat high to meld the flavors.

Pour in the cornstarch slurry while stirring continuously to thicken the sauce for about a minute until glossy.

Transfer your completed Beef Stir-fry with Vegetables to a serving platter. Serve individually over steamed rice or noodles.