1 pound medium shrimp, peeled, tails intact, deveined
1/2 lemongrass stalk, tough outer layer removed, lightly smashed, finely chopped
1 Fresno chile, with seeds, finely chopped
2 garlic cloves, finely chopped
1 teaspoon kosher salt
1 teaspoon sugar
8 oz. rice vermicelli noodles
Vegetable oil (for grilling)
1/2 cucumber, peeled, cut into thin strips
1 medium carrot, peeled, cut into thin strips
1/2 cup salted, roasted peanuts, coarsely chopped
Thai basil, mint, and/or cilantro sprigs, and pickled shallots for serving
Nuoc Cham for serving
Toss shrimp, lemongrass, chile, garlic, salt, and sugar in a medium bowl. Cover and chill at least 1 hour.
Cook noodles according to package directions. Using tongs or a spider, transfer noodles to a colander and run under cold water to stop cooking; set aside.
Prepare grill for medium-high heat; oil grill grate. Grill shrimp until cooked through, about 2 minutes per side.
Top noodles with shrimp, cucumber, carrot, peanuts, herbs, and Pickled Whole Shallots, and serve with Nuoc Cham.
DO AHEAD: Shrimp can be marinated 12 hours ahead. Cover and chill.