First cut the aubergines into smallish pieces, then place them in a colander and sprinkle with 2 heaped teaspoons of salt. Put a plate on top of them with a weight on it and leave them to drain for an hour.
Then, when you’re ready to cook them, preheat the oven to 190˚C/345˚F/gas mark 5 and butter a shallow baking dish.
Drain and dry the aubergines as thoroughly as possible on kitchen paper, then heat the oil in a frying pan. When it’s hot, add the aubergines and fry until they’re a pale golden colour.
Now add the onion to the pan and continue cooking until it has softened slightly; then add the tomatoes, crushed garlic and parsley, together with the spices, sugar and seasoning.
Simmer gently now, stirring a bit, for about 5 minutes. Next transfer the mixture to the baking dish, sprinkle the top with a mixture of cheese and breadcrumbs, and dot the surface with the butter.
Then bake on a high shelf in the oven for about 30 minutes, or until bubbling and browned on top.