A dressed-up rice vinegar lively with the tastes of serrano chili and lemongrass. Shop for Marukan rice vinegar with the green label (unseasoned), which is easily found, or the harder to find but equally good Mitsukan.
Those who avoid chili can simply omit it here.
3cupsunseasoned Japanese rice vinegar
½cupquarter-size thin coins fresh ginger, smashed
1 fat or 2 thinner stalks fresh lemongrass, pounded, then cut crosswise into finger lengths
6green and/or red serrano chilis, tipped and halved
Combine all of the ingredients in a non-aluminum pot, then bring to a simmer over moderate heat. Remove the pot from the heat and let stand until cool.
Store the mixture in an impeccably clean glass jar. If you wish, you may strain out the solids before storing, but do not press down on them while doing so. Another alternative is to leave only the chilis in the jar for color. The vinegar may cloud, but its flavor will not be affected.