Cut 2 medium eggplants into ¼in / 5mm slices, sprinkle with salt, and leave for at least 30 minutes.
Meanwhile, simmer 600ml of tomato passata with a little olive oil, a few basil leaves, and 2 garlic cloves, covered, over low heat for about 30 minutes. Season with salt and pepper.
Rinse and dry the eggplant and coat it in 100g of all-purpose flour. Fry in batches in 500ml of extra virgin olive oil until browned, then drain on paper towels.
Preheat the oven to 350°F / 180°C. Layer sauce, eggplant, 300g of sliced fresh mozzarella, and 300g of grated Parmigiano Reggiano in a 9 × 13in / 23 × 33cm baking dish, finishing with sauce and Parmigiano.
Bake for about 30 minutes, broiling for the last 3 minutes until browned. Rest for 10 minutes before serving.
