In non-metallic ovenproof dish, combine all ingredients, except for sesame seeds, with large pinch of salt. Cover and chill for at least 8 hours, or up to 2 days.
Preheat oven to 220C. Turn chicken skin-side up, baste well and put in oven. Immediately reduce temperature to 190C and roast for 35mins, basting occasionally, till golden; after 25mins, sprinkle seasme seeds over skin. Serve warm (or cold for picnic).
Recipe by tasty at http://tasty.haribotech.co.uk/?p=524