Preheat oven to 375. Brush eggplant rounds with olive oil and season with salt and pepper. Heat 2 tablespoons of oil in large non stick skillet and brown eggplant over medium high heat. Remove to a paper towel to drain. Heat 2 tablespoons of olive oil in same large skillet and cook onion and garlic for 3 minutes. Add the ground beef and brown completely. Add the spices, and tomatoes. Bring to a simmer and cook for 10 minutes. In a second non stick skillet, heat 3 tablespoons olive oil and brown potato slices on both sides. Remove to a paper towel to drain and season with salt and pepper. In a buttered baking dish, layer potatoes, meat, eggplant and top with Parmesan. In a medium bowl, combine yogurt, eggs and cream. Season with salt and pepper and pour over casserole. Let casserole sit for 10 minutes and then bake for 30 - 40 minutes or until golden brown and bubbly. Allow casserole to sit for 15 minutes before serving.