Add olive oil to a skillet. Place over medium-high heat and add the diced onion. Cook for 5 minutes, then add the diced garlic, basil, and oregano. Cook for 5 minutes, stirring occasionally. Pour in the tomato passata and diced tomatoes. Stir, bring to a boil, then reduce the heat to medium-low and cook for 15 - 20 minutes.
prepare the eggplants
Cut the eggplants into 1 cm (1/2-inch) thick slices. Season with salt and pepper on both sides. Spread flour over a baking sheet and roll the eggplants in the flour, shaking off any excess. Transfer the eggplants to a plate. Discard the flour, clean the baking sheet. Whisk the eggs in a bowl, then pour the eggs onto a baking sheet. Dip the eggplants into the eggs on both sides. Place a large skillet with the canola oil over medium-high heat. When the oil is hot, and reaches 175°C/340°F, add the first batch of eggplants. Make sure they aren't overcrowded. Fry for 2 - 3 minutes per side. Line a wire rack with paper towels and transfer the eggplants on the towels to drain any excess fat. Preheat your oven to 180 °C / 350 °F.
Add three tablespoons of the homemade tomato sauce to a 30 cm X 20 cm or 12-inch x 8-inch baking dish. Arrange the eggplants on top of the sauce. Spread the tomato sauce over the eggplants and sprinkle with the mixture of shredded Scarmoza cheese and shredded Parmesan cheese. Following with a layer of eggplants, tomato sauce, and cheese mixture until you get four layers. The last layer should be the tomato sauce. Then, arrange sliced Mozzarella cheese on top and sprinkle with a reserved tablespoon of shredded Parmesan cheese. Cover the baking dish with aluminum foil (making sure that the foil doesn't touch the food) and place it in the preheated oven. First, bake covered for 20 minutes at 180 °C / 350 °F, then discard the foil, and continue to bake for 15 - 20 minutes.TipTo prevent any spilling, feel free to place the baking dish on a baking sheet when baking.
Remove the baked Eggplant Parmesan from the oven and set aside for 5 minutes. Cut into 6 portions, sprinkle with fresh basil and serve.