Thinly slice the aubergines lengthways, then salt the slices. Preheat your oven to 200ºC
Bring he passata to a simmer in a saucepan with salt, pepper, oregano and half of the fresh basil and cook for 20-25 minutes until slightly thickened
Rinse the aubergine slices, then fry until golden on both sides. Once cooked, set on kitchen roll to soak up any excess oil. Beat the egg
Pour some of the tomato sauce into an oven dish, just enough to coat the bottom, then top with half of the aubergine, mozzarella, half of the parmesan, basil and beaten egg
Top with more tomato sauce and the remaining aubergine and tomato sauce, then sprinkle the rest of the parmesan over the top along with butter. Bake for 30-40 minutes until the top is browned and the sauce is bubbling, serve and enjoy!