Place the passata in a small saucepan over medium-low heat and simmer, stirring occasionally, for 10 minutes until reduced by about one-third and then allow to cool.
Combine parmesan and breadcrumbs in a bowl and set aside.
Heat 2mm oil in a large frypan and shallow fry the eggplant, in batches, for 2 minutes each side or until golden, adding more oil if necessary and then drain on paper towel and season with salt and pepper.
Preheat oven to 190°C.
To assemble the pie, lay half eggplant slices, overlapping, over the base of a 22cm ovenproof frypan (skillet), arranging them so they reach 2cm up the sides.
Spoon over one-third of the parmesan mixture and place half the mozzarella on top.
Repeat with passata, parmesan and mozzarella, then spoon over remaining passata and cover with the remaining eggplant, then scatter with the remaining parmesan mixture and bake in the oven for 35 minutes or until heated through.
Cool to room temperature and then turn the pie out onto a plate and cut into wedges.