Make the sauce:
Heat the olive oil in a pan over medium heat.
Add the leek and cook until soft.
Add the tomato paste, capers and chopped sun-dried tomatoes. Season with salt, pepper and oregano. Cook until hot.
Assemble the casserole:
Place half of the roasted eggplant slices on a baking sheet, spread with half of the sauce and sprinkle with half of the grated mozzarella. Add a layer of roasted potato slices and repeat with the remaining eggplant, sauce and mozzarella.
Baking:
Sprinkle with grated Parmesan cheese.
Bake for 20-25 minutes or until cheese is melted and bubbly.
Serving:
Let cool slightly before serving. Garnish with dried oregano.
Serving tips: