We top this moussaka with a mixture of yogurt and eggs, which is lighter than the traditional béchamel, or white sauce.

Cut lengthwise into slabs about ⅓ inch thick:

Salt the slices generously and place on a baking sheet lined with paper towels. Let stand for 30 minutes to 1 hour.

Meanwhile, heat a large skillet over medium-high heat and add:

Cook, stirring, until the meat has browned and rendered its fat, 3 to 5 minutes. Using a slotted spoon, transfer the meat to a bowl. Pour off all but 2 tablespoons fat from the skillet (if the meat has rendered less, add enough olive oil to make 2 tablespoons). Add and cook, stirring, until tender, about 5 minutes:

Scrape the bottom of the skillet with a wooden spatula as the onion cooks to scrape up any browned bits. Add and cook, stirring, until fragrant, about 30 seconds:

Return the meat to the skillet and stir in:

Bring to a simmer, then reduce the heat to low, cover, and simmer, stirring occasionally, until the mixture is thick and very fragrant, about 1 hour. Uncover and cook until the liquid in the skillet is just about gone, another 5 to 10 minutes. Remove from the heat and remove the bay leaf. Taste and adjust the seasonings. Let cool slightly, then stir in:

Preheat the oven to 350°F. Grease a 13 × 9-inch baking dish.

Rinse and pat the eggplant dry. Make an even layer of half the eggplant in the bottom of the dish, and spread all the sauce over the eggplant. Top with the remaining eggplant. Bake, covered with foil, for 30 minutes.

Meanwhile, beat together in a bowl:

Remove the foil and pour the yogurt/egg mixture over the eggplant. Sprinkle evenly over the top:

Return to the oven and bake until the topping is golden, another 25 to 30 minutes. Serve warm.