Pad thai is available on street corners across Thailand, but if you live elsewhere, you will probably need to go to a restaurant to get your fix. Making it at home requires a lot of preparation, but it is not difficult.
Unlike many versions of pad thai, which have a red hue from ketchup, this one uses paprika. Use regular (or "sweet") paprika, not the hot or smoked type.
There are various types of Chiu Chow preserved radish, including sweet and salty (get the sweet version), and they come in large chunks or thin strips (buy the latter). It's very intense, and is usually used as a condiment, rather than a refreshing pickle side dish. If you can't get the Chiu Chow version, then substitute Japanese or Korean pickled radish (called takuan or danmuji, respectively), although the flavour of the pad thai will be different.
Look for the preserved radish, rice noodles (also called rice sticks) and tamarind pulp in shops that specialise in Southeast Asian and East Asian ingredients, and in well-stocked grocery stores.
Put the rice noodles in a large bowl and add enough hot water to cover. Leave to soak until pliable. Put the tamarind pulp in a bowl and cover with 150ml (2/3 cup) of hot water. Soak until the water is cool, then strain the tamarind through a sieve placed over a small saucepan, pressing on the solids to extract as much flavour as possible. Discard the pulp in the sieve.
Add the palm sugar, paprika, fish sauce and half a teaspoon of salt to the pan with the tamarind liquid. Place the pan over a medium flame and bring to a simmer, then cook until the sugar is dissolved. Simmer for one minute, then take the pan from the flame.
Rinse the preserved radish with cold water, then squeeze out the excess liquid. Finely chop the radish. Cut the tofu into 1cm (7/16in) cubes. Remove the heads, shells and veins from the prawns. Halve the shallots, then thinly slice them. Roughly chop the garlic. Cut the garlic chives into 3cm (1¼in) lengths. Rinse the bean sprouts, then let them air-dry in a colander. Roughly chop the peanuts.
Pour about 40ml (2tbsp and 2tsp) of cooking oil into a large wok (or skillet) and heat over a medium flame. When the oil is hot, add the shallot and stir almost constantly for one minute, then mix in the garlic and chopped radish and stir for another minute. The shallot and garlic should be soft but not browned. Remove the ingredients from the wok, leaving behind as much oil as possible.
Put the tofu cubes into the wok and fry over a medium flame until pale golden, then remove the pieces from the wok and drain on paper towels. Turn the flame to high, then add the prawns and fry until curled, pink and cooked through (about one minute), stirring often. Remove the prawns from the wok and pour any remaining cooking oil into a bowl. Clean the wok.
Pour about 20ml (4tsp) of the oil used to cook the other ingredients back into the wok (if there's not enough, add some fresh oil) and heat over a medium flame. When the oil is hot, drain the noodles in a colander, shake to remove the excess water, then add them to the wok. Stir the tamarind/paprika sauce to recombine the ingredients, then slowly pour about 100ml of it into the wok.
Mix the ingredients in the wok, lifting the noodles and stirring gently so the noodles don’t break up too much. Cook until the noodles are tender and have evenly absorbed the sauce. If the noodles are too firm, mix in about 60ml (¼ cup) of water (or a little more of the tamarind sauce, if you think it needs more flavour), cover the wok and let them cook, stirring occasionally. When ready, all the liquid will be absorbed into the noodles, which should be tender but not falling apart.
Push the noodles to one side of the wok. Break the eggs directly into the wok and cook them until set at the edges. Lift the noodles with a metal spatula, place them over the eggs and let them cook undisturbed for about 30 seconds. Add the radish, tofu cubes, prawns, shallot, garlic, garlic chives and bean sprouts into the wok and gently stir and lift the noodles to evenly distribute the ingredients, taking care to mix in the egg.
Put the pad thai on a serving dish and sprinkle with some of the chopped peanuts. Quickly mix a sauce by stirring 60ml of fish sauce with several roughly chopped bird’s-eye chillies. Serve the pad thai with small bowls containing the fish sauce/chilli mixture (use sparingly), granulated sugar, chilli flakes, lime wedges and the remaining chopped peanuts. Let each guest add the seasonings as they wish.