In modern Greek moussaka, which vegetable typically alternates with layers of minced meat beneath the béchamel topping?

Eggplant

The classic Greek version of moussaka, featuring layers of fried eggplant and creamy béchamel, was popularized by chef Nikolaos Tselementes in the 1920s. Although many regional variations exist, the eggplant is considered the essential foundation that gives the dish its signature texture and flavor.