Heat 1 gallon water in large pan until boiling. Add noodles and cook until just tender, about 5 minutes. Drain. Toss with 1-2 teaspoons sesame oil. Immediately transfer noodles to round cake pan or pie plate. Press top to level noodles and let cool. This can be made a day ahead and refridgerated. In the meantime, cut leeks & re-hydrated mushroom caps into fine julienne strips. Discard mushroom stems. Rinse and drain bean sprouts. When noodles have cooled, combine broth, soy sauce, rice wine, sugar, 1 teaspoon sesame oil and cornstarch in bowl. Blend well. Heat well-seasoned wok or skillet until very hot. Add 1.5 tablespoons vegetable oil and heat until nearly smoking. Invert noodle cake into pan and cook until deep-golden brown, swirling pan from time to time to keep cake from sticking. Flip noodle cake over and brown other side. Transfer noodles to heat-proof serving platter and keep warm in oven at 200 degrees. Reheat pan and add remaining 1.5 tablespoons vegetable oil. Again, heat until very hot. Add garlic and ginger-root and stir-fry until fragrant, about 10 seconds. Add mushrooms, carrots, and leeks. Stir-fry over high heat about 1 minute. Add rice wine and cook one minute more. Then add sauce mixture and bring to boil. Add bean sprouts and cook, stirring constantly to prevent lumps, until sauce is thickened. Spoon vegetables over fried noodle cake and serve immediately.