3 bunches scallions, halved lengthwise and cut into 1-inch pieces
1/2 cup roasted salted peanuts, chopped (optional), plus more for garnish
2 cups cilantro sprigs
Lime wedges and red pepper flakes, to serve
Directions
For the tamarind sauce: In a small saucepan, bring 6 cups of water to a boil. Place the tamarind pods in a small bowl and pour the boiling water over the pods. Allow the pods to soak until very soft, about 1 hour. Using a slotted spoon, carefully place the pods in a fine-mesh strainer. Return the strainer to the water. Using your hands or a rubber spatula, press the tamarind through the strainer back into the soaking liquid. Discard the seeds and pods from the strainer. To the tamarind liquid, add the palm sugar, remaining 3/4 cup water, and the fish sauce. Stir to dissolve the sugar. Set aside.
For the pickled radishes: In a small bowl or glass jar, combine the radishes with the sea salt and vinegar. Stir or shake well to combine and dissolve the salt. Allow the radishes to pickle at room temperature for 30 minutes or up to 1 hour before refrigerating until ready to use.
For the stir fry: Place the noodles in a large bowl. Cover the noodles with warm water and allow them to soak until tender but still a bit firm, 30 to 40 minutes. Drain well.
Using paper towels, dry the duck breasts very well. Score the skin of the duck with 1-inch crosshatches, being careful not to cut all the way through the fat into the meat. Season the breasts evenly with the salt and five-spice powder. Heat a wok over medium heat and add the duck breasts, skin-side down, to the dry pan. Cook undisturbed until the skin is golden brown, crispy, and the fat has rendered, about 10 minutes. Flip the breasts and cook until the meat side is golden brown, about 5 minutes longer. Transfer to a plate to rest for 10 minutes. Slice the breasts across the grain into thin slices.
Drain the pickled radish. Return the wok with the duck fat to medium-high heat. Add enough additional duck fat to the pan to equal 1 cup. Heat until melted and hot, another 30 seconds. Carefully add the eggs all at once and sprinkle the drained radish and jerky on one side of the egg. When the egg is mostly set and beginning to brown around the edges, stir together the egg and jerky mixture. Add the soaked noodles and sprouts to the wok and toss well to combine. Cook, stirring and tossing often, until the noodles have softened, about 2 minutes.
Add half of the tamarind sauce to the wok and cook, stirring constantly, until the noodles are coated and the sauce has reduced and thickened, about 3 minutes. Taste, and adjust the amount of sauce to your liking. Add the scallions, sliced duck, and peanuts, if using, and toss well to combine and warm though. Serve immediately garnished with cilantro, lime wedges, red pepper flakes, and more peanuts if using.