Clean and slice the mushrooms. Deseed the tomato and cut it into chunks. Clean and chop the bok choi white stem and green leaves.
Heat oil in a wok or skillet. Add the minced ginger, coriander stalks, scallion, and garlic, sautéing for about 30 seconds until fragrant over high heat.
1 tablespoon sesame oil, ½ tablespoon minced garlic, ½ tablespoon minced ginger, 5 - 6 coriander stalks, finely chopped, 2 sprig scallions, finely chopped
In the same pan, add the sliced mushrooms and let them sear untouched for 5 minutes. Stir-fry until lightly browned and caramelized without adding salt.
200 gram brown mushroom, sliced
Pour in the vegetable stock and Shaoxing rice wine, soy sauce, and chilli sauce. Season with salt and pepper, bringing the liquid to a gentle simmer.
1 ½ Cup vegetable stock, 1 teaspoon light soy sauce, 1 teaspoon red chilli sauce, ¼ teaspoon salt or to taste, black pepper to taste
Re-stir your potato starch slurry and pour it in slowly into the sauce while stirring constantly until a glossy, light white gravy forms. Stir constantly to prevent clumps.
1 tablespoon corn starch or potato starch
Add the tomato wedges and bok choi. Simmer gently for 2 – 3 minutes just to warm them through without letting them break down completely.
1 large tomato, deseeded and diced, 1 large bok choi (whites and greens, chopped)
Once the sauce thickens and has a nice glossy glaze, it is ready to serve. Turn off the heat. Add chopped green onion and toasted sesame seeds.
1 teaspoon white sesame seeds, 2 sprig scallions, finely chopped