Start by slicing the eggplants, zucchini, and potatoes into ¼-inch rounds. Salt the eggplant slices and let them sit for 30 minutes, then pat dry.

In a large skillet, heat olive oil and fry the eggplant, zucchini, and potato slices in batches until golden brown, about 3–4 minutes per side. Transfer to paper towels.

In a large pot, sauté chopped onion until translucent, add minced garlic and ground meat, and cook until browned. Add red wine and simmer, then stir in crushed tomatoes, spices, and herbs, simmering for 10–15 minutes.

In a medium saucepan, melt butter and whisk in flour, then slowly add milk, stirring continuously until thickened. Mix in egg yolks, a pinch of nutmeg, and cheese until smooth.

Layer half of the potatoes, followed by fried eggplant, zucchini, and meat sauce. Repeat the layers, finishing with béchamel sauce.

Preheat oven to 175°C (350°F) and bake for 40–45 minutes. Let rest for 30 minutes before slicing.