Bring a 6-quart / 5.7 L pot of salted water to a boil. Cook the pastitsio pasta 1 to 2 minutes less than the package instructions, until just shy of al dente. Drain well.

Return the hot pasta to the pot. Stir in the 2 beaten eggs, 50 g grated kefalotyri or parmesan, and 1 tbsp melted butter until the pasta is coated. Set aside.

Heat 2 tbsp olive oil in a 12-inch / 30 cm skillet over medium heat. Add the onion and cook for 4 to 5 minutes, until soft. Add the garlic and cook 1 minute, until fragrant.

Add the ground beef and cook for 6 to 8 minutes, breaking it up with a spoon, until no longer pink and lightly browned.

Stir in the tomato paste and cook 1 minute. Add the crushed tomatoes, red wine, cinnamon stick, bay leaf, salt, pepper, and sugar. Simmer uncovered for 20 to 25 minutes, stirring occasionally, until thick and holding its shape on a spoon. Remove the cinnamon stick and bay leaf.

Melt 80 g butter in a 2-quart / 1.9 L saucepan over medium heat. Whisk in the flour and cook for 1 to 2 minutes, until it smells toasted but hasn't browned.

Pour in the milk in a slow stream, whisking constantly to avoid lumps. Cook for 8 to 10 minutes, whisking often, until the sauce is thick enough to coat the back of a spoon.

Take the pan off the heat. Whisk in the egg yolks, 50 g grated kefalotyri or parmesan, nutmeg, and salt until smooth.

Heat the oven to 180C / 350F. Spread half the pasta in a 9x13-inch / 23x33 cm baking dish. Top with all the meat sauce in an even layer, then the rest of the pasta.

Pour the bechamel over the top, spreading it to the edges. Sprinkle with the remaining 50 g grated kefalotyri or parmesan.

Bake for 40 to 45 minutes, until the top is golden brown and set, it shouldn't jiggle when you nudge the dish.

Let the pastitsio rest for 15 minutes before cutting into squares. Cut too soon and the layers slide apart.