Wash and stud the aubergine with a fork, brush with olive oil and brush with olive oil, roast until the aubergine is soft. Allow cooling slightly, cut in half and scoop out the pulp, mash the pulp and allow cooling completely. Mix together with the ricotta, egg, chopped herbs, prawns, salt and pepper. Cook paccheri in boiling salted water according to packet instructions. Refresh under cold running water and drizzle with some oil in order not to stick. Fill the paccheri with the aubergine filling and place on a baking tray, brush with melted butter and sprinkle liberally with bread crumbs and grated cheese. Bake in a hot oven until breadcrumbs are golden. Serve on warmed tomato and cream sauce.