Cut the aubergines into 5 mm (1/4 inch) slices and put them in a colander in layers, sprinkling salt between each layer. Cover with a plate and place a heavy weight on top. Leave for about 1 hour to draw out the bitter juices, then rinse the slices under cold running water and pat dry on absorbent paper.

Heat the oven to 180°C (350°F) Gas 4. Grease a shallow baking dish.

Pour enough of the oil into a large frying-pan to cover the base. Heat the oil, put a layer of aubergine slices in the pan and fry for 3-4 minutes on each side, turning once, until golden brown on both sides. Remove from the pan and drain on absorbent paper. Continue in the same way until all the aubergine slices are browned.

Place layers of aubergines and cheese alternately in prepared dish, finishing with a layer of cheese on top.

Put the egg, canned tomatoes, onion, tomato puree and water in a blender and blend until smooth. Season with a little salt and pepper, then pour over the aubergines and the cheese. Arrange the tomato slices on top.

Bake, uncovered, for 25 minutes, until heated through and bubbling. Serve straight from the dish.