Preheat your oven to 180°C (350°F). Slice the Eggplant into 1–1.5 cm (about 1/2 inch) rounds and the Potato into similar-thickness rounds.
Salt the eggplant slices lightly with Salt and let them sweat in a colander for 20 minutes, then rinse and pat dry with paper towels.
Brush or toss the eggplant and potato slices with Olive oil, season with a little Black pepper and extra Salt to taste, and either roast on baking sheets until golden and tender (20–30 minutes, turning once) or fry in a skillet until nicely browned. Set aside.
Make the meat sauce: heat a splash of Olive oil in a large skillet over medium heat and sauté the chopped Onion until translucent, then add the minced Garlic and cook 1 minute more.
Add the Ground beef and cook, breaking it up, until browned. Pour in the Dry red wine to deglaze the pan and let it reduce for a couple of minutes.
Stir in the Canned crushed tomatoes, Tomato paste, a pinch of Ground cinnamon and Ground allspice, plus the Dried oregano and the Bay leaf. Season with Salt and Black pepper, then simmer gently for 20–30 minutes until thickened. Stir in chopped Flat-leaf parsley at the end and discard the bay leaf.
Prepare the béchamel: melt the Unsalted butter in a saucepan over medium heat, whisk in the All-purpose flour and cook 1–2 minutes to form a blond roux.
Gradually whisk in warmed Whole milk and continue to cook, whisking, until the sauce is smooth and has thickened to a pouring consistency. Off the heat, temper in beaten Eggs (beat the eggs first and add a ladle of hot sauce to the eggs to warm them before whisking them back into the pot) to enrich the sauce.
Stir in most of the grated Kefalotyri cheese, then season the béchamel with a pinch of Ground nutmeg, White pepper and a little Salt to taste.
Assemble the moussaka in a deep baking dish: spread a single layer of the roasted potatoes across the bottom, top with half the eggplant slices, spoon over the meat sauce evenly, then cover with the remaining eggplant.
Pour the béchamel over the layered vegetables and meat, smoothing the surface. Sprinkle the remaining Kefalotyri cheese and a light dusting of Fine breadcrumbs over the top for a golden crust.
Bake in the preheated oven for 40–50 minutes, until the top is set and deeply golden. Let the moussaka rest for at least 20–30 minutes before slicing so the layers hold together.
Serve warm, garnished with a little extra chopped Flat-leaf parsley if you like.
