The first mystery is what leaf wafts the exotic aroma. The second is what hides inside, like a party favor (shrimp fit the form perfectly). It would be less trouble to serve the leaves raw, as is done in Asia, but the flavor is far too fierce for most Western palates. Blanching rounds it out, while the hint of pastis (fennel- or anise-flavored aperitif) highlights the herbaceous leaves rather than adding a new note. Serve the hot morsels with a chilled rosé.