Rinse and dry ahandful of mixed fresh herbs, or use half that amount of dried herbs. Place in a 1-litre/1¾-pint/1-quart jar or bottle. Add 10whole peppercorns, 2 peeled shallots and 1teaspoon celery seed. Fill up with cider vinegar, then seal and store for 2 weeks. Strain through muslin/cheesecloth and bottle.