For this hearty noodle recipe, chef Jonathan Wu braises lamb shoulder in a complex, concentrated syrup of smoked plums (typically diluted with water to make a refreshing drink called suanmeitang) before combining it with thick noodles, loads of dill, and pickled and fried peanuts for a touch of acidity. Even in well-stocked Chinese markets, the syrup can be hard to find; look for it in the tea or sweetener section with other flavored syrups. You can also make your own syrup by simmering equal weights of smoked plums (wu mei), dried hawthorn berry, osmanthus blossoms, Chinese licorice, and rock sugar in water for 2 hours over low heat until the mixture has a consistency like maple syrup.
- Make the pickled peanuts: Combine peanuts with sherry vinegar, cover, and let marinate for 24 hours. Drain off the vinegar, pat the peanuts very dry with paper towels, and lightly toss in confectioners’ sugar. Heat canola oil in a tall, narrow saucepan over medium heat until oil reaches 375 degrees, then add half the peanuts and fry until amber and fragrant, 1 to 2 minutes. Remove the peanuts to drain well on paper towels and season immediately with kosher salt. Repeat with the second half of the peanuts.
- Braise the lamb: Heat an oven to 300 degrees. In a Dutch oven, heat oil over medium-high heat until it shimmers, then add lamb in a single layer and season with salt. Lightly brown lamb on all sides, then remove to a plate and add the ginger, scallion whites, garlic, and onion to the Dutch oven and cook, stirring frequently, until fragrant, 1 to 2 minutes. Return the lamb to the Dutch oven and cover with plum concentrate, hoisin sauce, rice vinegar, brown sugar, and light and dark soy sauce. Stir to combine and bring mixture to a simmer, then cover the pot and transfer it to the oven. Braise until lamb is fork tender, 3 to 4 hours.
- Transfer the lamb pieces to a bowl to let cool for 10 minutes. Meanwhile, carefully strain all solid pieces out of the braising liquid. Use 2 forks or your hands to shred the lamb into bite-size pieces, then combine with strained braising liquid in a medium saucepan. Keep mixture warm over low heat.
- Char the scallions: Heat a dry cast-iron skillet over high heat until it begins to smoke, about 7 minutes, then add scallions in a single layer. Let them char slightly with black spots before turning them to a new side. Char on all sides, about 6 minutes total, then set aside to cool. Once cooled, cut them into 1-inch lengths.
- To assemble: Cook noodles according to package instructions, drain and rinse in a colander, and divide the noodles into 4 bowls. Top with lamb and braising liquid, then garnish each bowl with a few pieces of charred scallion, several pieces of freshly torn dill, and 1 to 2 tablespoons fried peanuts.