Preparation Halve chicken breasts lengthwise, then cut across the grain into 1/4-inch-thick slices and put in a bowl. Add sesame oil and a pinch of salt to chicken and stir to coat. Stir together broth, oyster sauce, ketjap manis, soy sauce, and sambal oelek in another small bowl. Holding carrot at a 45-degree angle to slicer, cut carrot into thin (-inch) matchsticks. Cut choy sum crosswise into 2 1/2- to 3-inch pieces, then halve any thick stem pieces lengthwise. Heat wok over high heat until a drop of water evaporates instantly. Swirl 1 tablespoon peanut oil to coat bottom and sides of wok. When oil begins to smoke, stir-fry sausage until browned, about 1 minute. Add chicken and stir-fry until just opaque, about 3 minutes. Transfer to a clean bowl (chicken will not be cooked through). Add remaining 2 tablespoons peanut oil to wok, swirling to coat, then stir-fry carrot, shallots, garlic, and chile 3 minutes. Add choy sum, bean sprouts, and scallions and stir-fry until choy sum is crisp-tender, about 3 minutes. Stir in broth mixture and bring to a boil. Add noodles and gently stir-fry until heated through and noodles are tender. Return sausage and chicken to wok and stir-fry until chicken is just cooked through, about 1 minute. Serve sprinkled with cilantro.
Preparation Halve chicken breasts lengthwise, then cut across the grain into 1/4-inch-thick slices and put in a bowl. Add sesame oil and a pinch of salt to chicken and stir to coat. Stir together broth, oyster sauce, ketjap manis, soy sauce, and sambal oelek in another small bowl. Holding carrot at a 45-degree angle to slicer, cut carrot into thin (-inch) matchsticks. Cut choy sum crosswise into 2 1/2- to 3-inch pieces, then halve any thick stem pieces lengthwise. Heat wok over high heat until a drop of water evaporates instantly. Swirl 1 tablespoon peanut oil to coat bottom and sides of wok. When oil begins to smoke, stir-fry sausage until browned, about 1 minute. Add chicken and stir-fry until just opaque, about 3 minutes. Transfer to a clean bowl (chicken will not be cooked through). Add remaining 2 tablespoons peanut oil to wok, swirling to coat, then stir-fry carrot, shallots, garlic, and chile 3 minutes. Add choy sum, bean sprouts, and scallions and stir-fry until choy sum is crisp-tender, about 3 minutes. Stir in broth mixture and bring to a boil. Add noodles and gently stir-fry until heated through and noodles are tender. Return sausage and chicken to wok and stir-fry until chicken is just cooked through, about 1 minute. Serve sprinkled with cilantro.