Heat oil in wok over high heat. Add garlic and sauté for 10 seconds, then add the chicken and cook until the outside of the chicken turns white (but inside is still pink). Add the carrots and bok choy stems and stir fry for 30 seconds, then add the sauce, chilli bean sauce and water and cook for 30 seconds to 1 minute until the sauce thickens. Toss in the bean sprouts and bok choy leaves, give it a quick stir then remove from heat and serve immediately.