In large skillet add olive oil and sauté onion until soft and transparent. In another skillet or wok add the meat, cook until browned. Mix tomato paste with meat. Continue cooking, adding the onions, nutmeg, salt, pepper, and cinnamon.
Cook until all the ingredients are incorporated in one brownish looking well done meat sauce take off heat to cool. Set aside. Cook the pasta in boiling water until half done, Drain and set aside.
Bechamel sauce prep
In a saucepan, melt the butter on a very low heat, As soon as it melts add the flour and stir with a wooden spoon until there are no lumps, and increase the heat to medium-low. Add the milk slowly, stirring constantly with a whisk, and continue stirring until the sauce begins to thicken without being too thick. Remove from the heat and stir in salt, pepper, and nutmeg. Stir in the egg yolks and return to the heat, whisking briskly until well blended.
Grease with olive oil an 8x12 baking oven glass Pan and Spread half the cooked pasta over the bottom of the dish. Spread all of the meat sauce over the pasta, spread the rest of the pasta over it, pour the Bechamel sauce on top and smooth with a spatula.