First, prep the sauce. Place 2 tablespoons of olive oil, the tomato passata, and a pinch of salt into a saucepan. slowly bring to the boil, and allow to cook for 30 minutes. then add in the basil, and allow to cook for a further 15 - 20 min.
While the sauce is cooking, slice the aubergine into 5mm slices.
Then in a large plate, start to layering the aubergine, sea salt and kitchen towel. first a piece of kitchen towel, then a layer of aubergine, and then sprinkle some salt over it to draw out the water and bitterness. Then repeat the layers, starting again with the paper towel. leave them for about 50 minutes so that all the moisture draws out.
When the sauce is done, and the aubergines have been sitting for a while. It is time to cook the aubergines. Add some olive oil (3 Tbsp) to a frying pan on a medium heat. Fry the aubergine (in batches) until just soft (about 3min each side). when they are cooked, leave them to rest on a paper towel until all the aubergine is cooked.
*you may need to top up the olive oil as you cook.
Now everything is cooked, time to layer! In an oven dish (mine was about 30cm long and 20 cm wide), add a little bit (3 tablespoons) of sauce, and smooth out. This is just so that the aubergine does not stick. You then add 1 layer of aubergine, then a light layer of grated Parmigiano, and then a few pieces of the mozzarella.
Start the layers again, first the sauce (enough to just cover the cheese), then the aubergine, then the Parmigiano and the mozzarella. Do this until the aubergine is done, and you end with sauce and cheese on top.
It's ready to cook! I made mine in the morning, so it was in the fridge until dinner time. But you can cook straight away - it may need less time as it will still be a bit warm. Preheat the oven to 200 degrees Celcius, and then bake the Melanzane for 40 min or until the cheese on top is golden brown and bubbling a little.
And enjoy :)