Step 1

Preheat the oven to 450°F. Grease two baking sheets. Arrange the potato slices on one baking sheet, and the eggplant slices on the other, overlapping slices as needed. Bake until cooked through, about 20 minutes. Set aside, and reduce the oven setting to 400°. Editor's Tip: Eggplant softens a bit when it's salted since salt draws the moisture out. If you'd like, sprinkle salt over both sides of the slices before baking, then let them sit on paper towels for about 15 minutes. This pulls the moisture out of the eggplant while taking away some of the bitterness.

Step 2

In a large skillet over medium-high heat, cook the lamb, onion and garlic until the meat is no longer pink, seven to nine minutes, using a wooden spoon or spatula to break up the meat as it cooks. Drain. Stir in the tomatoes, water, tomato paste, 1/4 teaspoon salt, oregano, paprika, cinnamon and 1/4 teaspoon nutmeg. Bring to a boil. Reduce the heat, and simmer, uncovered, for five minutes. Set aside while you make the bechamel.

Step 3

In a large saucepan, melt the butter over medium heat. Whisk in the flour until smooth. Gradually whisk in the milk. Bring the mixture to a boil, stirring constantly. Cook and stir until thickened, two to three minutes. Stir in remaining 1 teaspoon salt and 1/4 teaspoon nutmeg.

Step 4

Grease a 13x9-inch baking dish. Arrange the parcooked potato slices on the bottom of the dish, overlapping as needed. Top with the lamb mixture, then the eggplant, overlapping slices as needed. Pour the bechamel over the top, then even it out with a spatula. Sprinkle the mozzarella cheese over top. Bake, uncovered, until bubbly and golden brown, about 30 minutes, rotating the dish halfway through. Allow the dish to stand for 20 minutes before serving.