In a bowl, soak noodles in hot water for about 5 minutes. Drain and set aside. In a small bowl, combine fish sauce, tamarind juice, sugar, and vinegar and set aside.
In a large skillet, heat oil on medium-high. Saute shallots until translucent. Add tofu to brown slightly, followed by shrimp. Cook for about 2 minutes, and then add the soaked noodles. Pour the sauce over the noodles and mix well. Make space in the pan to scramble the egg. Mix with the noodles, along with chives and peanuts.
To assemble, Plate the noodles and top with more chives or scallions, peanuts, bean sprouts, chili powder, and lime wedges.