Instructions

Whisk ¼ cup water, 2 tablespoons oyster sauce, 1 tablespoon soy sauce, 1 teaspoon sugar, and ¼ teaspoon pepper together in bowl; set sauce aside. Bring 2 quarts water to boil in large saucepan. Add 6 ounces fresh Chinese noodles and cook, stirring often, until tender. Drain noodles and rinse thoroughly with cold water, shaking to remove excess water. Toss noodles with 1 tablespoon sesame oil in bowl and set aside until ready to serve.
Heat 1 tablespoon vegetable oil in 12-inch nonstick skillet over medium-high heat until just smoking. Add 8 ounces boneless, skinless chicken breasts, trimmed, halved lengthwise, and sliced thin crosswise, in single layer and cook without stirring for 1 minute. Stir and continue to cook until lightly browned on both sides, about 1 minute longer. Add 6 ounces shiitake mushrooms, stemmed and sliced thin, and 1 carrot, peeled and sliced thin on bias, and cook, stirring frequently, until vegetables are tender and mushrooms begin to brown, about 5 minutes. Stir in thinly sliced whites from 3 scallions and cook until fragrant, about 30 seconds. Off heat, stir in sauce.
Divide noodles among individual serving bowls then top with chicken mixture. Sprinkle with 2 teaspoons toasted sesame seeds and sprinkle with thinly sliced greens of 3 scallions.