Heat the oil in a frying pan and add the nigella seeds. When they start popping, add the ginger and garlic, and cook for 1 min. Add the squash, cabbage, spices and 1 tsp salt, then mix everything together well with a splash of water, covering the pan with a lid. Leave to steam for 7-8 mins over a low heat.

After this time, lift the lid to check if the squash is cooked. If not, replace the lid quickly and leave to cook a little longer. Add the lime juice and check for seasoning before serving with dhal, chutney and rice or roti, if you like.