Preheat the oven to 220°C (425°F). Lightly brush both sides of the eggplant and potato slices with olive oil. Arrange the slices on a baking sheet in a single layer and bake for 25 minutes, flipping halfway through, until they begin to brown.
2. Heat some olive oil in a pan over medium heat. Add minced garlic and sauté for 30 seconds, then add onions and cook until softened. Stir in the diced tomatoes and tomato sauce. Add sumac, cumin, dried mint, salt, and black pepper, stirring everything together. Let it cook for a few minutes, then add water and simmer until the sauce thickens slightly. Turn off the heat and mix in the chopped parsley.
Reduce the oven temperature to 190°C (375°F). In a small baking dish, spread a thin layer of the tomato sauce mixture. Layer half of the eggplant and potato slices over the sauce. Add a layer of sliced onions and tomatoes. Sprinkle half of the chickpeas over the vegetables.
Pour half of the remaining tomato sauce over the layers. Repeat the layering with the remaining eggplant, potatoes, onions, tomatoes, chickpeas, and sauce.
If the mixture appears too thick, add a small amount of water to thin the sauce slightly. Cover the baking dish with foil and bake for 25-30 minutes.
If using pine nuts (Optional), toast them in a small pan with olive oil over medium heat until golden brown. After baking, remove the foil and sprinkle the toasted pine nuts over the top. Garnish with fresh mint or parsley leaves before serving.
