Chop the onion and garlic finely in a blender. Pour some olive oil in a large non-stick pan and place it over medium heat until hot. Then add the onion mix.

Stir and cook gently for 5 minutes until the onion starts to soften. Then add the mince to the pan.

Break up the big lumps and stir. Cook for 6 minutes until the mince is brown and crumbly. Then add the canned tomatoes and chicken stock. Season with a dash of pepper, salt and half of the ground cinnamon.

Stir the ingredients well. Simmer the mince sauce gently for another 7 minutes. Then check the seasoning and add extra pepper, salt or cinnamon. The tomato sauce should be rather be thick. In the meantime bring a pan of water to a rolling boil and add the macaroni. Cook until the macaroni is tender and drain. Then transfer the cooked macaroni back to the pan and put aside until later.

Add the butter to a small saucepan and place it over medium heat until melted. Then add the plain flour.

Whisk firmly into a wet crumble and turn the heat low. Let the flour bake gently for about 2 minutes. Stir regularly. Turn the heat up again and add a little milk.

Stir well into a sticky mixture. Then gradually add the remaining milk. Stir well to break up any flour lumps. Once the milk is incorporated, let the sauce simmer and thicken. Stir regularly. Then add the egg yolk.

Stir quickly and season with a dash of pepper, salt and the remaining cinnamon to taste. Then add half of the sauce to the cooked macaroni and stir.

Top with the tomato sauce and cover this layer with the remaining macaroni. Finish with white sauce.

Make sure to cover the pasta well with the sauce. Bake the dish in a preheated over at 356°F (180°) for about 30 minutes. Keep an eye on the white sauce: it will start to turn brown. Cover with a piece of tinfoil if necessary. Once the pastitio is baked, remove it from the oven, cut it up into squares and serve hot.