Remove the outer leaves from the bamboo shoot until the heart is exposed. Cut the shoot lengthwise into halves. Then cut into slices about an 0.5cm thick. Set aside. Remove the stem of the mushrooms by cutting it off from the cap. Set aside.
Mix the cornstarch and 2 tbsp of water into a slurry. Set aside.
In a wok heat the vegetable oil until just at the smoking stage. Add the garlic and brown for about half a minute. Put in the bamboo shoots and the mushrooms and continue to stir-fry for about another minute. Be sure to stir constantly to prevent from burning. Then add white pepper, light soy sauce, oyster sauce, Shaoxing wine and clear stock. Cover the wok and turn the heat down to simmer for about 5 minutes.
In the meantime, blanch the bok choy in boiling water for about two minutes. Drain and arrange in a circle on a round shallow plate.
Uncover the wok with the bamboo shoots and mushrooms, and thicken the sauce with the cornstarch slurry.
Scoop the bamboo shoot and mushrooms over the bok choy and arrange decoratively. Serve immediately.