For the Vegetable Layers:

• 2 medium eggplants, sliced into 1/4-inch rounds
• 2 large zucchinis, sliced into 1/4-inch rounds
• 3 medium potatoes, sliced into 1/4-inch rounds
• 3 tablespoons olive oil
• Salt and pepper, to taste

For the Tomato Sauce:

• 1 tablespoon olive oil
• 1 onion, finely chopped
• 3 garlic cloves, minced
• 1 red bell pepper, diced
• 1 can (14 oz) diced tomatoes
• 2 tablespoons tomato paste
• 1 teaspoon ground cinnamon
• 1/2 teaspoon ground nutmeg
• 1/2 teaspoon dried oregano
• 1/2 teaspoon dried thyme
• Salt and pepper, to taste
• 1/2 cup red wine (optional)
• 1/4 cup fresh parsley, chopped

For the Béchamel Sauce:

• 4 tablespoons butter
• 4 tablespoons all-purpose flour
• 2 cups milk, warmed
• 1/4 cup grated Parmesan cheese
• 1/2 cup Greek yogurt or ricotta (optional for extra creaminess)
• Salt and pepper, to taste
• 1/4 teaspoon ground nutmeg
• 2 egg yolks