Fry the shallots with the mushrooms, garlic, thyme, bay leaf, sage and dried ham. Deglaze with the white wine. Reduce briefly. Add the water and the flakes. Reduce until desired consistency. Pass through a sieve. Finish with butter and season
Season the cod with salt and pepper. Fry one side and cook further in a preheated oven at 150 ° C
Dry the slices ham at 60 ° C
Cut the celeriac into the desired shape and boil until tender in salted water. Braise in butter and add some truffle shavings. Season to taste.