You could finish the ribs off on a barbecue instead of the oven if you prefer. Place the ribs in a large, wide saucepan. Cover with water and add the onion, garlic, fennel seeds and star anise.
When ready to reheat, place the whole pan, with the lid on, onto a barbecue on a low heat. Let the ribs warm through for about 2-3 hours. When warm, remove the lid and slowly reduce the glaze with ...