Slice the eggplants, zucchini, and potatoes into ¼-inch rounds. Sprinkle salt on the eggplant slices and set aside for 30 minutes.

Fry the eggplant, zucchini, and potato slices until golden and tender, about 3-4 minutes per side.

Sauté the chopped onion in olive oil until soft and translucent, about 5 minutes. Stir in minced garlic and cook for an additional minute.

Add the ground meat to the skillet and cook until browned, approximately 8-10 minutes. Pour in the red wine and allow to simmer.

Stir in the crushed tomatoes, cinnamon, nutmeg, oregano, thyme, and a pinch of salt and pepper, and simmer for 10-15 minutes.

In a saucepan, melt the butter, whisk in flour to create a roux, then gradually add milk and stir until thickened. Remove from heat and whisk in egg yolks and cheese.

Preheat oven to 165°C (330°F). Layer the fried potatoes, eggplant, zucchini, and half of the meat sauce in a baking dish. Repeat and top with béchamel sauce.

Bake for 40-45 minutes until the top is bubbling and golden brown. Let rest for at least 30 minutes before slicing.