Directions

Bring vinegar, sugars, salt, ginger, garlic, coriander, turmeric, and allspice to a boil in a large saucepan over medium-high. Cook, stirring constantly, until sugars have fully dissolved and mixture is slightly thickened, about 3 minutes.

Stir in sliced chiles (they will not be fully submerged). Return mixture to a boil over medium-high. Cook, stirring often, until chiles are glossy, softened, slightly shrunken, and darkened by a shade, 5 to 6 minutes.
Remove from heat. Using a slotted spoon, transfer chiles to a cleaned and sanitized 1-pint (2-cup) canning jar, lightly tapping jar on counter or pressing chiles to fit in jar.
Return remaining syrup to a boil over high; cook, stirring occasionally, until syrupy and reduced to about 1 cup, about 8 minutes.
Pour syrup over chiles in jar, leaving 1/4-inch headspace; discard any remaining syrup. Seal jar with lid. Cool slightly at room temperature, about 1 hour; refrigerate at least 48 hours or up to 2 months before serving.