1/2 cup thinly sliced ginger (2 1/2 ounces), lightly crushed with the side of
a knife blade
1/2 cup rice vinegar
1/4 cup sugar
6 dried red chiles, broken into several pieces
2 pounds large shrimp, shelled and deveined
4 cups small ice cubes
1/2 cup sweet Thai chili sauce
3 tablespoons fresh lime juice
2 tablespoons ketchup
1 1/2 teaspoons Asian fish sauce
Celery sticks and cucumber spears, for serving
In a small saucepan, combine the ginger with the vinegar, sugar and chiles. Bring to a boil, stirring to dissolve the sugar. Transfer to a large bowl; let cool.
In a large pot of boiling salted water, simmer the shrimp until pink and cooked through, about 2 minutes. Drain the shrimp and add them to the ginger mixture. Stir in the ice cubes and refrigerate for at least 4 hours or overnight. Drain the shrimp and pat dry. Discard the ginger and chiles.
In a small bowl, mix the Thai chili sauce with the lime juice, ketchup and fish sauce. Refrigerate until chilled. Arrange the shrimp on a platter with the celery sticks and cucumber spears and serve with the sauce.
The marinating shrimp and the dipping sauce can be refrigerated separately overnight.