Making moussaka is something of an undertaking—a rich meat sauce (made here with lamb, but you can substitute other ground meats such as turkey, veal, or even pork, if you prefer), layered with tender eggplant and a cheese sauce. You can make the moussaka in two smaller casserole dishes to serve one now and freeze one to bake later.
Many recipes instruct you to salt eggplant before you cook it. Some say this step is necessary because it draws out any bitterness in the eggplant. We think it's a good idea, even if the eggplant isn't large or bitter. Drawing out some of the moisture in eggplant collapses the vegetable a little, so it doesn't act as much like a sponge for oil when you fry it.
Peel the eggplant if you wish and slice the eggplant to the required thickness. Place the slices in a colander and put the colander in a large bowl. Sprinkle the slices liberally with kosher salt and let them rest until the salt begins to draw moisture to the surface, about 20 minutes. Rinse the eggplant thoroughly, let drain, and blot dry.
