Cook pasta al dente according to the instructions on the package. Once drained, do not rinse and set aside on a baking sheet. Drizzle with olive oil, sprinkle with Parmesan cheese and season with salt and pepper. Mix well.
Heat oil in a skillet over medium-high heat. Cook onion for 2 to 3 minutes, stirring occasionally. Add garlic and cook for 1 minute more, stirring.
Add the veal, season and cook for a few minutes, ensuring that the meat is well broken up.
Add chicken stock concentrate, cinnamon, sugar, mint, tomatoes and water.
Simmer for about 20 minutes or until the sauce reaches a nice consistency. Adjust seasoning and set aside.
In a saucepan, melt butter over medium heat, add flour and cook for 2 to 3 minutes, stirring constantly.
Whisk in the roux while pouring in half the milk until the mixture starts to bubble. Remove from heat.
Meanwhile, in a bowl, whisk the eggs with the remaining milk and add to the mixture in the pan. Return the saucepan to heat and let simmer until the mixture thickens. Add nutmeg, season to taste and let cool.
Grease the inside of an ovenproof dish and pour in half the sauce. Add macaroni and spread the other half of the sauce. Add feta cheese, cover evenly with bechamel sauce and sprinkle with the crumble.
Bake in the oven for about 1 hour until the topping is golden brown.