Preparation

• Bring a 3- to 4-quart saucepan of water to a boil over high heat. Meanwhile, soak the noodles in a bowl of cold water until pliable, about 7 minutes. Drain and boil, stirring once or twice, until tender, about 15 seconds. Transfer with tongs to a colander and immediately rinse under cold running water until cool. Drain and transfer to a bowl. Toss with the fish sauce, lime juice, and sesame oil and set aside.
• Add the shrimp and vinegar to the boiling water and cook the shrimp just until pink and opaque, about 2 minutes. Drain in a colander and rinse under cold running water until cool.
• Divide the rice noodles among the lettuce leaves. Top with the cucumber, carrots, shrimp, and peanuts. Sprinkle with the basil and serve with the Sriracha.