Be careful not to over-soak the wrappers, which will cause rolls to split when assembled. Look for rice paper wrappers, also known as banh trang, in the international foods section.
1 tsp. fish sauce
1 tsp. lime juice
1 tsp. vegetable oil
1?2 tsp. packed light brown sugar
1 cup cooked thin rice noodles (1 1/2 oz. dried), chilled
4 (8") rice paper wrappers
1?4 cup small mint leaves
1 scallion, sliced thin
12 large cooked shrimp (about 1?4 lb.), peeled, deveined, and halved lengthwise
1?2 mango, peeled and sliced thin
2 radishes, halved and sliced thin
Pinch salt