These crisp, salty-sweet chicken wings were inspired by the ones we tasted at Coupi Street Kitchen, a Vietnamese-inspired café in the Left Bank of Paris. A dusting of potato starch gives them a thin, crackly exterior, which stays crisp even after the wings have been sauced. High-impact ingredients, including fragrant lemon grass, punchy alliums and zingy chilies, bring big, bold flavor, while fish sauce, lime juice and sugar contribute sweet, tart and salty notes. After the wings are fried, the sauce is made separately, reduced in a skillet to a sticky glaze for coating the chicken. The recipe works with drumettes, flats (also called wingettes) or a combination. If you purchase whole wings, you will need to cut between the joints to separate the parts. Since the wing tips are not used in this recipe (if desired, they can be saved for making chicken broth), you may wish to opt for 2¼ pounds of wings, or even a little more.