01 -
Heat olive oil in a large pot over medium heat. Add chopped onions and a pinch of salt, sauté until translucent. Add ground beef and cook, stirring until browned and no longer pink. Stir in tomato sauce and cinnamon, season with salt. Simmer with lid slightly ajar for 3 hours, stirring occasionally. Cool and refrigerate overnight.
02 -
Grate kasseri cheese and set aside. Bring meat sauce to room temperature or warm gently. Cook pastitsio noodles in boiling salted water until slightly under al dente, drain, cool briefly, then toss with one beaten egg using hands.
03 -
Preheat oven to 175°C (350°F). Lightly grease a large baking dish with olive oil or cooking spray. Arrange noodles evenly in the bottom. Sprinkle one third of the grated cheese over noodles. Using a slotted spoon, spread all or most of the meat sauce evenly over cheese. Sprinkle another third of cheese atop meat layer.
04 -
In a heavy-bottomed pot, melt 1 stick (113 g) butter over medium heat. Whisk in flour and cook for 1-2 minutes. Gradually whisk in 5 cups (1.18 liters) milk, stirring until sauce thickens and bubbles. In a separate bowl, beat 3 eggs with ½ cup (120 ml) milk. Slowly whisk egg mixture into sauce. Return to medium-high heat, whisk continuously until thick and bubbly. Remove from heat and let rest briefly.
05 -
Melt remaining ½ stick (57 g) butter in a small saucepan. Pour béchamel evenly over meat and cheese layers. Sprinkle remaining cheese over béchamel. Drizzle melted butter atop cheese layer to encourage browning. Place baking dish on a baking sheet and bake for 1 hour, until golden and heated through. If needed, broil for 3-5 minutes watching closely to brown top evenly. Let rest 10 minutes before serving.