Step One Put the ginger, onion and garlic into the container of an electric blender along with 3 tablespoons water and blend until smooth. Wipe the mushrooms with a damp cloth and cut them into halves or quarters, depending upon size.

Step Two Put 3 tablespoons of the oil in a non-stick frying pan and set over high heat. When hot, put in the mushrooms. Stir and fry for 2–3 minutes or until the mushrooms have lost their raw look. Empty the contents of the pan into a bowl. Wipe the pan.

Step Three Put the remaining oil into the pan and set over high heat. When hot, add the paste from the blender. Stir and fry for 3–4 minutes until it starts turning brown. Add 1 tablespoon of the yoghurt and fry for 30 seconds. Add another tablespoon of the yoghurt and fry for 30 seconds. Do this a third time. Now add the tomato purée and fry for 30 seconds. Add the ground coriander and stir once or twice. Now put in 300ml (10fl oz) water, the mushrooms and their juices, salt and chilli powder. Stir and bring to a simmer. Turn the heat to low and simmer for 5 minutes. Sprinkle the green coriander over the top before serving.