In a large skillet over medium high heat, brown 1 1/2 pounds ground beef. Break up large pieces and cook until done but not overly crumbly. Add 1 medium yellow onion(halved and then thinly sliced), 1/2 red bell pepper(stem and seeds removed, thinly sliced), and 4 cloves garlic(minced), stir, and continue to cook until the vegetables are tender.
Add all 1 tablespoon kosher salt, 1 1/2 teaspoons all spice, 1 1/2 teaspoons cinnamon, 1 teaspoon black pepper, 1 tablespoon dried oregano, and 2 tablespoons tomato paste. Stir and cook for several minutes.
Add 1 cup red wine, stir, and cook until all of the liquid has absorbed or evaporated, about 5 minutes.
Add 28 ounces canned whole peeled tomatoes(pureed until smooth), stir, and simmer over low heat for about 20 minutes.
To make the Bechamel sauce:
Melt 6 tablespoons unsalted butter in a medium sized saucepan over medium high heat. Whisk in 1/2 cup all purpose flour, whisk constantly, and allow to cook until the flour is golden brown and smells heavenly. While continuously whisking, add in 2 1/2 cups milk and 1 bay leaf. Continue to cook while stirring until thickened. Stir in 1 teaspoon kosher salt, 1/2 teaspoon black pepper, and 1/8 teaspoon nutmeg. Discard bay leaf. Remove from heat.
Allow mixture to cool and when it is cool enough to touch, whisk in 3 egg yolks and the zest from one lemon until smooth.
To prepare the eggplant:
Remove half of the peel from the 2 pounds eggplant by peeling vertical strips. I like to remove half because I find that not removing any peel makes it too hard to eat, but I like some peel because it helps the pieces stay in tact. Slice into 1/4 inch thick rounds.
Combine 8 cups water and 1/2 cup salt in large bowl and stir until salt dissolves. Add eggplant slices to brine, weigh down with heavy lid to keep them submerged, and soak for at least 15 minutes.
Remove eggplant from brine. Set slices in single layer in between clean towels or paper towels and press to remove liquid.
You may have to do this next part in batches. Set eggplant slices in a single layer on a baking sheet and lightly coat with 2 tablespoons olive oil. Broil for a few minutes on each side, just to the point where they're softened and the edges begin to brown. Remove from oven and set aside.
To prepare the potatoes:
Peel and slice the potatoes into 1/4 inch rounds. Add 1 tablespoon salt to a large pot of water, bring to a boil, and 1 1/2 pounds gold potatoes. Cook them until they're slightly soft/slightly crunchy, about 5 minutes. They will continue cooking later in the oven. Drain and set aside.
To assemble Moussaka:
Preheat oven to 350°F.
Spread all of the potatoes across the bottom of an 11x17 baking dish. Spread half of the eggplant on top of the potatoes. Add all of the meat sauce on top of the eggplant, then top with the remaining eggplant. Cover everything with the Bechamel sauce and then top with 8 ounces Pecorino Romano cheese(grated).
Bake in preheated oven until browned and bubbly, about 35-40 minutes. Best if you let it cool for about 20 minutes before serving. Enjoy!