How to Make It
In a medium saucepan, heat the water, sugar and salt, stirring, until dissolved. Let cool. In a large bowl, pour the brine over the chicken wings. Cover and refrigerate for 4 hours; drain and pat dry.
Meanwhile, in a large heatproof bowl, combine the scallions, chile, ginger and lemongrass. In a small saucepan, heat the 1/2 cup of oil until almost smoking. Pour the hot oil over the scallion mixture and let stand until cooled. Add the wings, toss to coat and refrigerate overnight.
In a large saucepan, heat 2 inches of oil to 350°. Drain the wings. In a medium bowl, toss the wings in the tapioca flour mixture until well coated. Fry the wings in batches until golden and cooked through, about 7 minutes per batch. Drain on paper towels, sprinkle with the cilantro and serve with lime wedges.