Sprinkle the aubergine slices with salt and leave to stand for 30 minutes. Rinse under cold water and dry thoroughly with absorbent kitchen paper.

Melt the butter in a non-stick frying pan, add the onion and garlic and fry until lightly browned. Stir in the tomatoes and cook for 20 - 25 minutes, until thickened.

Heat the oil in another non-stick pan and fry the aubergine slices until browned on both sides. Drain thoroughly on absorbent - kitchen paper.

Line the base and sides of a 1.5 litre (2 1/2 pint) charlotte mould with aubergine slices. Fill with layers of the tomato mixture, yogurt and aubergines, finishing with aubergines. Cover with foil and cook in the oven for 40-45 minutes, until tender.

Leave for 10 minutes, then turn out on to a warmed serving dish. Heat any remaining tomato sauce with the stock and spoon around the charlotte.

Sliced or halved aubergines should always be sprinkled with salt and left to stand as this will draw out the bitter juices.