Instructions

for the chile vinegar

Combine ⅓ cup distilled white vinegar and 1 stemmed and sliced serrano chile in bowl and let stand at room temperature for at least 15 minutes.

for the stir-fry

Combine ¼ cup water, ½ teaspoon table salt, and ¼ teaspoon sugar in small bowl. Microwave until steaming, about 30 seconds. Add 2 radishes, cut into 1½-inch by ¼-inch matchsticks, and let stand for 15 minutes. Drain and pat dry with paper towels.
Bring 6 cups water to boil. Place 8 ounces wide rice noodles in large bowl. Pour boiling water over noodles. Stir, then let soak until noodles are almost tender, about 8 minutes, stirring once halfway through soaking. Drain noodles and rinse with cold water. Drain noodles well, then toss with 2 teaspoons vegetable oil.
Combine ¼ cup fish sauce, 3 tablespoons tamarind juice concentrate, and 3 tablespoons sugar in bowl and whisk until sugar is dissolved. Set sauce aside.
Peel and devein 1 pound large shrimp. Remove tails from 4 shrimp. Cut shrimp in half lengthwise, then cut each half into ½-inch pieces. Toss shrimp pieces with ⅛ teaspoon table salt and ⅛ teaspoon sugar. Arrange pieces in single layer on large plate and microwave at 50 percent power until shrimp are dried and have reduced in size by half, 4 to 5 minutes. (Check halfway through microwaving and separate any pieces that may have stuck together.)
Heat 2 teaspoons vegetable oil in 12-inch nonstick skillet over medium heat until shimmering. Add dried shrimp and cook, stirring frequently, until golden brown and crispy, 3 to 5 minutes. Transfer to large bowl.
Heat 1 teaspoon vegetable oil in now-empty skillet over medium heat until shimmering. Add minced whites of 4 scallions and 1 minced garlic clove and cook, stirring constantly, until garlic is golden brown, about 1 minute. Transfer to bowl with dried shrimp.
Heat 2 teaspoons vegetable oil in now-empty skillet over high heat until just smoking. Add remaining whole shrimp and spread into even layer. Cook, without stirring, until shrimp turn opaque and brown around edges, 2 to 3 minutes, flipping halfway through cooking. Push shrimp to sides of skillet. Add 2 teaspoons vegetable oil to center, then add 4 lightly beaten large eggs to center. Using silicone spatula, stir eggs gently and cook until set but still wet. Stir eggs into shrimp and continue to cook, breaking up large pieces of egg, until eggs are fully cooked, 30 to 60 seconds longer. Transfer shrimp-egg mixture to bowl with scallion-garlic mixture and dried shrimp.
Heat remaining 2 teaspoons oil in now-empty skillet over high heat until just smoking. Add noodles and sauce and toss with tongs to coat. Cook, stirring and tossing often, until noodles are tender and have absorbed sauce, 2 to 4 minutes.
Transfer noodles to bowl with shrimp mixture. Add 2 teaspoons chile vinegar, drained radishes, greens of 4 scallions, cut into 1-inch pieces, and 2 cups bean sprouts and toss to combine. Transfer to platter and sprinkle with ¼ cup coarsely chopped roasted unsalted peanuts. Serve immediately, passing lime wedges and remaining chile vinegar separately.