Soak the egg noodles in hot water for 5 minutes, drain, and then set them aside.
For the vinegar: Put the white wine vinegar, sugar, and chile oil into a bowl. Season the mixture with salt, to taste, and set aside. Add the chives to the flavored vinegar just before serving.
For the egg: In a nonstick saute pan, heat the vegetable oil over medium heat. Crack the eggs into the pan. Increase the heat to high, and add the butter. Cook the eggs until their bottoms are crisp and the yolks are runny. Switch off the heat, and set the eggs aside.
For the stir-fry: In a small bowl, stir the oyster sauce and water together, and set aside.
Heat the vegetable oil in a wok or a shallow, wide-bottomed pot, over high heat. Once smoking hot, add the red onion, and shiitake mushrooms, and toss for 1 minute. Add the garlic, and toss. Add the shrimp, and toss. Once the shrimp has turned pink, pour the oyster sauce and water mixture into the wok. Stir in the ginger and cooked noodles, then toss. Add the tomatoes and chopped green onions, then toss.
Remove the wok from the heat, and add the spinach, and toss. Divide the stir-fry among 4 warmed serving bowls, and layer 1 fried egg over each portion.
Spoon the flavored vinegar and chives over the fried egg.