With a chopstick or skewer, gently push the orange peel strip and fresh fennel sprig into a clean 12- to 16-ounce bottle. Remove hulls from cardamom pods; drop cardamom seeds into bottle. Also add coriander seed, and fennel seed if used. Pour vinegar through a funnel into bottle. Seal and store in a cool, dark place at room temperature for at least 1 week or up to 4 months.

* Use a vegetable peeler to cut a thin spiral strip of peel from an orange.