Lasagna

Prepare a Béchamel sauce (white sauce):
In a saucepan melt 30 g butter. (Keep the remaining 50 g out of the refrigerator to bring it to room temperature).
Heat the milk.
Add to melted butter, off the heat, 1.5 tsp. flour, stirring with 1 whisk.
Put over medium heat and pour in small amounts of hot milk, while beating (until thickening of the preparation).
Adjust the amount of milk to the desired creaminess/texture.
Add one of the grated nutmeg or even a little cayenne pepper.
Add 2/3 of the parmesan (grated), and mix.
(This is the sauce invented to flatter the Marquis de Béchamel, maître d'hôtel of the French king Louis XIV.)
Keep aside.

Rinse and chop the basil leaves.

Peel and dice the onion and carrot.
Peel, degerm and crush the garlic.
Fry the onion and carrot in a pan with the hot oil, then add the beef, garlic and sausage meat.
Cook on a high heat, stirring to dry the mixture.
Salt and pepper, and add to the bechamel (keeping a bit of bechamel aside).
Toss well.
Preheat the oven to 210 °C (410 °F).

In another pan, cook the diced tomatoes with the tomato purée.
Season with salt and pepper, then add basil.

Butter a gratin dish.
Mount the preparation:
1 layer of lasagna,
Brush with a little olive oil (so that the dough does not become wet - this is a protection)
1 layer of meat,
1 layer of tomato,
1 layer of lasagna lightly brushed with olive oil
...
On the last layer of lasagna, put only the remaining béchamel, grate the rest of parmesan and sprinkle some chips of butter.
Put in the oven for 30 minutes.

Serve hot.

In season use of course fresh tomatoes (peel and seed them).
This dish is equivalent to the Hachis Parmentier one (potatoes are replaced by pasta). If possible, avoid preground meat. Select instead a piece of meat and get it ground in front of you. This dish often used to be done with... horse meat.
For a veggie version of the dish, replace the meat with layers of peppers (peeled, seeded then confit in coarse salt for 2-3 hours), or fried eggplants and onion slices.