Start with the minced meat by placing a large and deep saucepan over medium heat. Pour the 3 tablespoons of oil and add the onions, sauté for 3-4 minutes until they become translucent.
Add the minced meat, increase the heat and continue sauteing until all the meat has been sautéed and a nice color has been achieved.
Add the tomatoes, reduce the heat to low, add the Worcestershire sauce, the nutmeg, the all-spice powder, sea salt and pepper and stir for a minute or so. Add the tomato paste and simmer while stirring for 10 minutes for all the ingredients to come together. Keep aside.
It’s time for the Pasta! In a Large pot bring water to a boil on high heat adding a generous amount of salt. Add the pasta, stirring occasionally so as not to stick and cook 2 minutes less than package instructions. Strain and keep aside.
It’s Béchamel time!!
In a medium pot boil the milk on low heat. Keep aside.
In a large non-stick pot over low heat add the butter, whisk, and once melted start adding the flour and keep on whisking to be just enough thick, a nice roux.
At this point start adding the warm milk, a bit at a time and keep on whisking. Add the nutmeg, salt and pepper and continue adding the milk and keep on whisking aiming to achieve a nice, not too runny cream.
TO PUT EVERYTHING TOGETHER:
Preheat the oven to the 180 degrees C, air circulation, rack in the middle.
In a large (~40 CM) rectangular non-stick oven dish that deep enough (6-7 cm) add the pasta and pour on it half the appenzeller cheese. Add to the pasta couple of spoons from the béchamel cream and spread evenly.
Add the minced meat on the pasta and with a wooden spoon spread evenly, pressing lightly.
Add on top the Béchamel cream, spread and sprinkle with the remaining cheeses and cook for 1 hour.
Take out of the oven and let rest, cut in adorable squares!