Pot-au-feu: beef, oxtail and bone marrow simmered with root vegetables and bouquet garni

Soak the marrow bones in cold water with a splash of white vinegar or a tablespoon of salt and refrigerate overnight to bleach out the blood and firm the marrow.

Drain and rinse the bones; optionally scrape off remaining flesh.

Optionally wrap each bone in gauze, marrow side up: season the marrow with a good pinch of gray salt and tie with butcher's twine. Set salted side up in a saucepan and refrigerate until ready to cook.

Cut the root vegetables into 2-inch (5 cm) chunks; keep them in water if prepped ahead.

Keep only the light green leek stems for the stew; clean them by soaking in warm water about 15 minutes, changing the water until it runs clean, and tie them in small bundles.

Peel the potatoes and keep them in water.

Make the bouquet garni: wrap bay leaves, thyme, carrot and celery in a couple of leek leaves and tie with twine. Halve the garlic head.

Tie the beef cuts and oxtail with twine so they keep their shape.

Put the meat (not the marrow bones) in a stockpot with the garlic, bouquet garni, salt, peppercorns, cold water and white chicken stock.

Make onion brulee: cook halved onion cut side down on high heat with no fat until dark brown, stud with cloves and add to the pot.

Bring to a boil, then hold at a bare simmer for two and a half hours, skimming the scum.

Discard the bouquet garni, garlic and onion and keep cooking slowly.

Cover the marrow bones with some of the broth in their own pan and cook on low heat 25 minutes; remove the marrow and reserve.

Return the broth to the stockpot, discarding the cloudy broth left at the bottom.

Add the root vegetables (not the potatoes) and cook 30 minutes; turn off the heat and let it infuse, then cool and chill overnight.

Cook the potatoes in salted water with fresh thyme; reheat the marrow and meat.

Serve hot with whole grain mustard, salt and cornichons.