Making the meat sauce: Pour the olive oil into a medium pan and set over medium-high heat. Throw in the onion, garlic and celery. Fry until colouring.
Mix in the minced beef. Turn up the heat to high and fry for 3 or 4 minutes, stirring with the wooden spoon.
Pour in the red wine.
Tip in the tomatoes, tomato purée, cinnamon stick, ground cloves, dried and fresh oregano, bay leaves, 100ml water, 1½ teaspoons salt and some black pepper. Stew for about 30 to 40 minutes, stirring from time to time, until the sauce becomes thick. Remove the cinnamon stick and bay leaves.
Cooking the pasta: Pour 4.5l of water into a large saucepan. Add 8 teaspoons of salt then bring to the boil. Throw in the pasta and boil until they are al dente. Strain then tip into a large bowl. Set aside to cool.
Making the white sauce: Heat the butter in a medium non-stick saucepan set over medium heat. Once melted, stir in the flour and cook for about 1 minute. Whisk in the milk, little by little. Bring to the boil while stirring constantly. Turn down the heat then simmer for about 5 to 7 minutes, stirring from time to time. Sprinkle with nutmeg, salt and pepper.
Heat the oven to 180°C. Pour 1/5 of the white sauce (about 250ml) into the pasta. Mix in the beaten eggs and half of the grated cheese. Keep the rest of the white sauce warm over low heat, stirring from time to time. If the sauce starts to thicken, pour in a little milk.
Grease a large, shallow 23cm x 33cm x 7cm ovenproof dish with the melted butter. Spoon 1/3 of the pasta into the dish and even out. Top with half of the meat sauce. Repeat then add the last layer of pasta.
Cover with the rest of the white sauce. Top with the remaining grated cheese mixed with the breadcrumbs.
Put in the oven for about 40 minutes, until it becomes golden and small bubbles start to form on top.