Prepare the chicken: Whisk the egg white, cornstarch and rice wine in a bowl. Add the chicken and toss to coat. Cover and refrigerate at least 30 minutes. Make the stir-fry sauce: Whisk 1/3 cup water, the oyster, hoisin and soy sauces, the rice wine and sesame oil in a bowl, then whisk in the cornstarch until dissolved.
Fry the noodles: Pull the noodles apart into sections. Heat 3/4 inch peanut oil in a medium saucepan until a deep-fry thermometer registers 380 degrees F. Working in batches, press the noodles into the oil with a spatula until they puff, 5 to 10 seconds. Drain on paper towels.
Make the stir-fry: Heat 2 tablespoons peanut oil in a large skillet over medium-high heat. Add the chicken and cook, stirring, 2 to 3 minutes. Remove with a slotted spoon to a plate. Add the remaining 2 tablespoons peanut oil to the skillet; when almost smoking, stir in the garlic, ginger, jalapeno and minced scallions, then add 1/2 teaspoon salt and the sugar and stir-fry 30 seconds. Add the mushrooms, water chestnuts and scallion pieces and stir-fry 2 minutes. Add the stir-fry sauce and chicken and cook 1 minute. Make a bed of noodles on a platter and top with the chicken mixture. Serve the noodles and stir-fry with lettuce leaves and soy sauce for dipping. Photograph by Andrew Mccaul