Preheat oven to 375°F (190°C).
Slice eggplants, sprinkle with salt, and let sit for 30 minutes. Rinse and pat dry.
In a frying pan, heat olive oil and fry eggplant slices until golden. Set aside.
In the same pan, sauté onions and garlic until soft. Add ground beef and cook until browned.
Add tomatoes, cinnamon, salt, and pepper. Simmer for 20 minutes.
For the béchamel sauce, melt butter in a saucepan, add flour, and cook for 2 minutes. Gradually add milk, stirring constantly until thickened. Add nutmeg and salt.
In a baking dish, layer half the eggplants, then the meat sauce, and then the remaining eggplants. Pour béchamel sauce on top and sprinkle with grated cheese.
Bake for 45 minutes or until golden brown.
Let it cool for 10 minutes before serving.