Step 1

Heat the oil in a large, deep frying pan and fry the onions for 5 minutes over a medium heat, then add the cooked potato and fry for another 5 minutes until golden. If you don't have any leftover potatoes, bring a pan of water to the boil and cook your potatoes until just tender, then cut into roughly 2cm/¾in chunks and fry with the onions. Tip into a bowl and set aside.

Step 2

Add a little more oil to the pan, reduce the heat slightly and add the curry powder, ginger and chilli. Stir for a minute or two.

Step 3

Add the garlic and fry for 30 seconds, then add the tomatoes, sugar and 50ml/2fl oz water. Cook for 10–15 minutes until the sauce has thickened.

Step 4

Add the chopped greens and allow to wilt, then return the cooked potatoes and onions to the pan. Season with salt and cook for 5–10 minutes more.

Step 5

Serve with basmati rice and yoghurt or raita.