Prepare the eggplant and potatoes:
Sprinkle salt on eggplant slices and let them rest for 30 minutes to remove bitterness. Rinse and pat dry.
Fry or bake the eggplant and potato slices until golden, then set aside.
Cook the meat sauce:
Heat olive oil in a pan, sauté onions and garlic until soft.
Add ground beef, cook until browned.
Stir in tomatoes, tomato paste, red wine, and spices. Simmer for 20 minutes until thick.
Make the béchamel sauce:
Melt butter in a saucepan, whisk in flour, and cook for 1-2 minutes.
Gradually add milk, stirring until smooth.
Remove from heat, whisk in egg yolk, cheese, salt, and nutmeg.
Assemble the moussaka:
Preheat oven to 180°C (350°F).
Layer potatoes at the bottom of a baking dish, followed by half of the eggplant slices.
Spread the meat sauce evenly, then layer the remaining eggplant.
Pour the béchamel sauce over the top, spreading evenly.
Sprinkle shredded cheese on top.
Bake and serve:
Bake for 45-50 minutes until golden brown.
Let it rest for 10-15 minutes before serving.
