Sprinkle the wings with a little salt and refrigerate for 15 minutes. Meanwhile preheat the oven to 200 degrees C and line a metal baking sheet with foil and lightly coat with cooking spray or oil.

Arrange the wings in rows on the tray and roast in the oven for 20 minutes till golden brown. Turn the wings and roast for a further 20 minutes.

Meanwhile make the sauce. In a mortar, pound together the coriander root, garlic, red chillies and chilli paste into a thick, almost homogeneous mixture. Heat a pan on low flame and drop in the butter followed by the mixture from the mortar. Now mix in the ketchup, soy, vinegar and fish sauce (if using) and simmer gently for 5 minutes. If the sauce is too thick, dilute with water as required. Remove from the heat when the sauce reaches the consistency of a thick yet smooth spread.

Once the wings are golden and cooked on both sides,remove from the oven and turn on the broiler. Now baste the wings generously with the sauce and return to the oven to brown under the broiler for a total of no more than 5 minutes (this is to crisp up the wings but take care that they do not overcook and dry up). Serve with extra sauce on the side.