1. Cut the eggplants lengthwise ½ in (13cm) thick. Place in a colander on a plate and toss with 1½ tbsp of salt. Let stand 30–60 minutes to draw out the bitter juices. Rinse well and pat dry with paper towels.

2. Position an oiled broiler rack 6in (15cm) from the heat and preheat the broiler. Broil the eggplant, peppers, and mushrooms for 5–10 minutes, or until they are softened but still hold their shape. Season to taste with salt and pepper.

3. Preheat the oven to 375°F (190°C). Lightly oil the baking dish and spoon in a ladleful of the marinara sauce. Top with a layer of pasta, some vegetables, another ladleful of sauce, then some of the mozzarella and ricotta. Repeat the layers, finishing with tomato sauce, topped with some vegetables. Sprinkle with the Parmesan.

4. Cover the dish tightly with aluminium foil and place on a baking sheet. Bake for 30 minutes. Remove the foil and bake for 15 minutes more to brown the top. Remove from the oven and let stand 15 minutes before serving.