Thinly slice the aubergines and sprinkle with salt. Place in a colander in the sink or suspended over a large bowl. Leave for 30 minutes while they lose their bitter liquid.
Preheat oven to 180 C / Gas mark 4. Lightly grease a 23x33cm (9x13 in) baking dish with olive oil.
Meanwhile, sauté the onions, garlic, and olive oil in a large frying pan over low heat, covering the pan with a lid to keep them moist. Sauté the onions until they are soft and translucent.
Add the basil, oregano, passata, water, salt and pepper to the onions. Simmer 10 minutes.
Rinse off the aubergine slices and place them on a baking tray lightly greased with olive oil to prevent sticking. Place in preheated oven and bake for 5 to 10 minutes while tomato mixture is simmering.
In the prepared baking dish, spread 2 to 3 tablespoons of the tomato mixture over the bottom.
Remove aubergines from the oven and arrange one layer of aubergines on the bottom of the dish. Pour one third of the tomato mixture over the aubergine. Pour half of the yoghurt over the tomato mixture. Repeat the layers and top with the remaining tomato m
Cover dish with foil and bake for 30 minutes. Uncover and sprinkle the wheatgerm or breadcrumbs over the top, followed by the Parmesan cheese. Bake for another 20 to 30 minutes or until topping is golden brown and aubergines are soft.
Parmesan cheese is not truly vegetarian, as it contains animal rennet. To make this dish 100% vegetarian, omit the cheese or find a suitable vegetarian substitute made without animal rennet. In supermarkets look for the 'parmesan style hard cheeses' which are suitable for vegetarians.
Agree with Cupcake about the yogurt - I couldn't really see what it added within the dish. A realy good low fat recipe - I grilled the aubergine on my 'Lean mean griller' and used a low fat pitta to make the breadcrumbs - the parmesan was a treat on our 'low fat diet' - 27 Feb 2012