Maria's Musakà / Musakà di Maria

Directions

1. In a large saucepan, melt the butter.  Stir in the flour and cook over medium heat,stirring until well blended.  Lower the heat and slowly whisk in the milk until smooth. Add the salt, raise the heat to medium-high, and cook, stirring, until the sauce has thickened.  Cover and set aside.  (The sauce can be made a day ahead, cooled, covered, and refrigerated. Thin it with a little milk if it has thickened too much, and reheat over low heat before assembling the musakà.)
2. Put the potatoes in a large pot, cover with cold salted water, and bring to a boil. Cook until tender.  Drain and let cool, then peel and thinly slice.  Set aside.
3. Layer the eggplant in a large pot, sprinkling each layer with salt.  Cover and cook the eggplant over low heat for about 5 minutes, or just until it starts to get soft.  Remove the lid and cook for another 10 minutes.  Drain in a colander and set aside.
4. Preheat the oven to 350°F.  Spread a thin layer of the white sauce in an 11 by 8-inch casserole dish or baking pan. Add a layer of eggplant and a thin layer of tomato sauce.  Sprinkle on a little of the grated cheese and add a layer of potatoes.  Cover with another layer of white sauce and continue layering, ending with a layer of potatoes covered with white sauce and sprinkled with cheese.
5. Bake for 20 to 30 minutes or until the sauce is bubbly and the top has browned.  Let sit for 10 minutes before scooping out or cutting into squares.