Lay out eggplant on absorbant kitchen paper, sprinkle liberally with salt and leave 30 minutes to leach out bitterness.
Rinse the salt off, pat dry and fry gently in olive oil. Drain on paper.
Spread a thin layer of sauce in the bottom of casserole; top with a layer of eggplant, a little of the Parmesan cheese, and top with a layer of mozzarella slices. Repeat this procedure until all eggplant is used, ending with mozzarella.
Bake in a preheated 400 F (205 C) oven for 15-20 minutes or until cheese is melted.
