Preheat the oven to 180°C conventional oven/ 160°C fan-forced (350° Fahrenheit/Gas 4). Grease a baking dish with butter or margarine.
Slice the eggplant into 1cm thick rounds, then cut into 4 – see note.
Pour enough oil into a large frying pan to generously cover the base. Add the eggplant and cook over medium heat, stirring occasionally, until soft and golden (approximately 5 minutes). Season the eggplant with salt as you cook them and transfer to a plate lined with paper towel.
To make the Italian tomato sauce, place the olive oil in a heavy-based stockpot over medium heat. Add the onion and cook until soft. Add the Italian passata and water. Bring to the boil, then add the basil, a pinch of salt and the sugar. Add the cooked eggplant. Reduce the heat to low and simmer for approximately 45 minutes or until the sauce has reduced to your required consistency, stirring occasionally so that the sauce does not stick to the pot and burn, then remove from the heat. Add additional water, where required. Set aside 1/4 of the Italian tomato sauce.
Meanwhile place a large pot with water on high heat and bring to the boil. Add a pinch of salt and rigatoni pasta to the boiling water and cook for 3/4 of the ‘al dente’ cooking time – refer to the cooking time specified in pasta packet instructions. Drain the pasta, then add to the stockpot with the remaining Italian tomato sauce and eggplant. Gently toss to combine.
Spread the Italian tomato sauce (that was set aside) over the base of the baking dish. Add 1/2 of the rigatoni pasta with Italian tomato sauce and eggplant, then use the back of a ladle to press it down and level it. Add a layer using 1/2 of the Provolone cheese cubes. Sprinkle 1/3 of the Parmigiano Reggiano cheese on top of the Provolone. Continue layering using the remaining rigatoni pasta with Italian tomato sauce and eggplant (once again pressing it down with a ladle) and Provolone cheese. Finish with a layer using the remaining Parmigiano Reggiano sprinkled to cover the pasta al forno (pasta bake). Drizzle extra virgin olive oil on top.
Bake in a preheated oven for 25 minutes. Change to the grill setting of the oven (same oven temperature). Brown under the grill for 5 minutes or until lightly golden on top. Remove from the oven and allow to rest for a minimum of 10 minutes before serving.
Cut the Eggplant (aubergine) pasta al forno (pasta bake) into 6 portions and serve – buon appetito.
Note: In Italy, there are excellent varieties of melanzane (eggplant/aubergine) that are rounded and a vibrant purple colour such as ‘Rosa Bianca’, ‘Violetta di Firenze’, ‘Bianca Sfumata di Rosa’, and ‘Prosperosa’. These varieties have a more delicate flavour and are not bitter. In Australia, I choose Graffiti eggplant (also known as Sicilian eggplant) – they are less seedy and also not bitter. The Italian varieties above and Graffiti eggplant do not need to be salted and rinsed before cooking.
If you are using a black-skinned eggplant, however, you will need to salt the eggplant. To do this, slice the eggplant as per step 3, sprinkle both sides of the eggplant slices with salt and layer in a colander. Set aside for 20 minutes to maximum of 1 hour. Rinse under cold water, drain and use paper towel to pat dry.