Slice the potatoes, zucchini, and eggplants into circular disks.

Heat the olive oil in a pan over medium-high heat and fry the vegetable slices until they are cooked and golden brown. Remove and drain on paper towels.

In a large pot over high heat, add the olive oil, finely chopped onion, and minced garlic. Cook until soft and translucent.

Add the beef mince and cook until browned, breaking it up as it cooks.

Pour in the red wine and let it simmer until mostly evaporated (about 3 minutes).

Stir in the crushed tomatoes and add the salt, white pepper, ground cinnamon, ground nutmeg, sugar, thyme, oregano, bay leaves, and chopped parsley. Mix well and bring to a simmer. Cook for about 10 minutes and then remove bay leaves.

In another saucepan over medium heat, melt the butter. Gradually add the flour while stirring until a smooth paste forms.

Slowly add the milk while stirring constantly until a thick, creamy texture is achieved.

Stir in the egg yolks, nutmeg, and shredded Kefalograviera cheese until combined. Cook until thickened and bubbling, then remove from heat.

Preheat the oven to 165°C (fan-forced).

Arrange the potato slices in a single layer in a baking dish, season with salt and pepper, and sprinkle with cheese.

Add a layer of eggplant slices, season, and sprinkle with cheese.

Layer the zucchini slices, season, and sprinkle with cheese.

Add another layer of eggplant slices, season, and sprinkle with remaining cheese.

Pour the meat sauce evenly over the layered vegetables.

Top with béchamel sauce, spreading it evenly.

Bake for 40 minutes or until the top is golden brown. Check from 30 minutes onwards.

Let the moussaka rest for a minimum of 30 minutes before slicing. Cut into portions and serve.