The tamarind sauce can be refrigerated for up to 2 weeks.
In a small bowl, combine tamarind paste and warm water. Massage to break up the tamarind paste, and then pass through a sieve to remove any seeds. In a small saucepan, combine the tamarind mixture, fish sauce, palm and brown sugar and bring to a boil. Lower to medium-low heat and cook 15 minutes more, then let the sauce cool.
In a large pan, preferably cast-iron, heat pork fat until almost smoking. Sear shrimp on both sides and them remove from pan. Add the egg on one side and then shallot on the other. Once the white begins to set, scramble the egg and mix with the shallots. Next add the smoked tofu, noodles and ½ cup cooled sauce. Add bean sprouts, peanuts, chives and chili flakes, and cook until noodles are soft. Remove from the pan, squeeze in ½ a lime and mix. Garnish with more bean sprouts, chopped peanuts, chives, cilantro and lime wedges.