Slice the eggplants, zucchini, and potatoes into 1/4 inch thick rounds. Sprinkle salt on eggplant and let sit for 30 minutes.

In a skillet, heat olive oil and fry the salted eggplant, zucchini, and potato slices until golden brown, about 3-4 minutes per side.

In a pot, heat olive oil, sauté chopped onion and minced garlic for 3-4 minutes. Add ground meat and cook until browned.

Pour in red wine and let simmer for 3 minutes, then stir in crushed tomatoes, cinnamon, nutmeg, oregano, thyme, salt, and pepper. Simmer uncovered for 10-15 minutes.

In a saucepan, melt butter, whisk in flour to create a roux. Slowly add milk while whisking continuously. Cook until thick.

Mix in egg yolks, nutmeg, and half of the cheese until smooth.

Layer in a baking dish: potatoes, eggplant, zucchini, and meat sauce, finishing with béchamel and remaining cheese on top.

Bake in a preheated oven at 180°C (350°F) for 40-45 minutes until golden and bubbly.

Let cool for 30 minutes before slicing to allow layers to firm up.