Slice 5 medium aubergines (1.25kg) into 3-4mm slices, sprinkle well with salt and lay on something that allows them to shed their water and drain away. After an hour, wash off the salt and pat dry. Fry in batches on a medium high hear to brown and set aside.
In a seperate saucepan, fry 2 onions and 3 garlic cloves to soften, then combine 4 tins of plum tomatoes with 4 pinches of salt and 4 pinches of sugar, 1 bay leaf and plenty of finely ground black pepper.
Grate 50g of parmesan or hard goats cheese then build the dish my making a complete layer of aubergine, followed by tomato sauce, followed by a sprinkling of cheese. Repeat this 3 or 4 times finishing with a chopped ball of mozzarella on the top layer.
Cook on 180C for 30 to 40 minutes.