Pastitsio is a classic Greek dish that is similar to baked ziti or lasagna. The dish has three main parts: pasta (ziti), tomato sauce with lamb, cinnamon, nutmeg, and allspice, as well as a bechamel sauce.
Add the olive oil to a large sauté pan over medium-high heat. Once hot, add the ground beer and lamb and cook for 5-6 minutes, or just until you do not see any more pink.
Add the onion and garlic and continue to cook until the onions are soft and the garlic is very fragrant, about 4-5 minutes. Salt and pepper generously.
Pour the white wine into the sauté pan and stir. Allow the wine to reduce by at least half before adding the tomato puree, oregano, 1 teaspoon cinnamon, 1 teaspoon nutmeg, and allspice.
Bring the sauce to a simmer and allow to simmer for 20-30 minutes or until the sauce is quick thick. Set aside.
While the tomato sauce is simmering, bring your water for the pasta in a stock pot to a boil. Cook the pasta as per the directions on the packaging except cut back the time by 1-2 minutes so that you don’t end up with super mushy noodles in the end.
While the pasta is cooking begin preparing the béchamel sauce by melting the butter in a large sauté pan. Once melted, slowly add the flour, whisking continuously to fully incorporate the fat and flour to make a roux. Continuing whisking for 2-3 minutes to cook out the raw flour taste.
Slowly add the milk to the roux, again whisking continuously.
Add the 1/2 teaspoon of nutmeg and allspice to the béchamel and let cook for 5 minutes. Remove from the heat.
Place the egg yolks in a small bowl, and, while mixing them continuously, slowly add a tablespoon of the béchamel to the yolks at a time. Do this 4 or 5 times to temper the eggs. Then add the egg mixture to the béchamel and whisk to combine fully. Set aside. Note: DO NOT dump the yolks directly into the hot béchamel sauce without tempering them first or else you will end up with scrambled eggs.
Preheat your oven to 375 degrees F.
Once the pasta is cooked, strain it. Place 1/2 cup of butter in the empty stock pot and, once melted, add the ziti along with the egg whites. Toss to combine but be careful not to break the noodles.
To assemble the pastitsio, in a 13 by 9 pyrex baking dish, apply a layer of cooking spray so that the food does not adhere to the dish. Then, spread the ziti across the bottom of the dish, being sure to evenly distribute the noodles. Then, place the tomato sauce on the ziti. Top the tomato sauce with the béchamel, making sure that the entire dish is covered. Sprinkle the freshly grated parmesan cheese on top and place in the over, uncovered, for 45 minutes or until the cheese and béchamel sauce start to brown slightly. Allow to rest for 5-10 minutes.
Serve by cutting square or rectangular pieces (just as if you were serving lasagna).