Sprinkle eggplant slices with salt and let them sit for 15 minutes to draw out bitterness. Rinse and pat dry.
2
Preheat oven to 180°C (350°F). Brush eggplant slices with 2 tablespoons of olive oil and bake for 20 minutes until tender.
3
In a large skillet, heat remaining olive oil and sauté onions and garlic until translucent.
4
Add ground beef or lamb, cooking until browned.
5
Stir in crushed tomatoes, cinnamon, nutmeg, salt, and pepper. Simmer for 20 minutes.
6
Meanwhile, prepare béchamel sauce: melt butter in a saucepan, whisk in flour, then slowly add milk, whisking constantly to avoid lumps. Cook until thickened.
7
Remove from heat, temper in eggs, and mix well. Add Parmesan cheese if using.
8
Layer half of the baked eggplant slices in a baking dish, spread the meat sauce over, then cover with remaining eggplant slices.