Vegetarian Eggplant Casserole

Prepare the eggplant and potatoes:
Preheat the oven to 200°C (400°F). Slice the eggplant, sprinkle with salt, and let it rest for 15–20 minutes to release moisture. Pat dry with paper towels.
Slice the potatoes, drizzle with olive oil, and season with salt, pepper, paprika, and dried oregano. Toss to coat.
Roast the vegetables:
Arrange the eggplant and potato slices on separate baking sheets.
Roast the potatoes for 15–20 minutes, or until tender and golden.
Roast the eggplant for 20–25 minutes, or until softened and golden. Remove from the oven and set aside.
Make the sauce:
Heat the olive oil in a saucepan over medium heat.
Add the leek and cook until softened.
Add the tomato puree, capers, and chopped sun-dried tomatoes. Season with salt, pepper, and oregano. Cook until hot.
Assemble the casserole:
In a baking dish, arrange half the roasted eggplant slices, spread half the sauce, and sprinkle half the grated mozzarella on top. Add a layer of roasted potato slices, then repeat with the remaining eggplant, sauce, and mozzarella.