Peel, wash, and dry the potatoes.
Grate them and put them on a towel.
Close the towel and press firmly to remove excess water.

Peel and chop the onions.
Chop 6 slices of bacon, reserve the rest for the finish.

Cook the bacon in a pan with a little oil.
Then add the chopped onions and cook over low heat for 5 minutes, stirring regularly.
Remove the sausage casing and add the meat to the pan, browning while breaking it up with a fork.

Preheat the oven to 350 F (180 C).
Rub a deep dish, preferably terracotta, with the garlic clove, then butter it.

Beat the eggs with the flour, mix with the milk, then add the thyme, marjoram, and nutmeg.
Season with salt and pepper.
Add the grated potatoes to the mixture and mix well.

Pour half of the potato mixture into the bottom of the dish.
Spread the bacon-onion-sausage mixture on top, then cover with the remaining potato mixture.
Arrange the remaining bacon slices on top, then bake for 1 hour.
Serve, sliced, with a salad.