Recipe is out of Healthy Thai Cooking Cookbook. It advises to use the fresh Chinese tofu (bean curd), and for best results to cook the noodles and tofu separately. Bring them together just before you serve the dish, hot, for lunch or supper.
Cook the noodles: boil 5 cups water with the salt and add the noodles. While they are boiling, separate them, with a large fork so that they cook evenly and don't stick together. Let them boil for 3 minutes, then transfer them to a colander and put them under cold running water until they are cool. Leave them in the colander to drain completely.
Heat half the oil in a wok and stir-fry the shallots, garlic, and ginger for 2 minutes. Add the soy sauce and tomatoes, and stir for 30 seconds.
Add the cold noodles and keep turning and tossing them around until they are hot again. Remove the wok from the heat and cover it, so that the noodles stay warm.
In another wok or frying pan, heat the remaining oil and add the chopped chilies and yellow bean sauce. Stir for 2 minutes. Raise the heat and add the lightly beaten eggs and scallions. With a wooden spoon, vigorously stir the mixture until the eggs are scrambled.
Transfer the tofu mixture to the wok with the noodles. Heat together over a low heat, stirring and mixing so that everything is evenly hot. Serve at once.