Preheat the oven to eighty degrees. Warm a plate with it.
Put the onions in boiling water and blanch for one minute. Drain and rinse when cool. Cut off the roots and squeeze the onions out of the skin. Make the onionettes in the soup for five min. Drain.
Prepare mushrooms (ready to cook, e.g. peel, remove woody parts and dirt), but leave them whole. Fry in hot butter, turning, for two to three minutes; if the mushrooms draw juice, evaporate it completely. Add to the onions form.
Season the veal chops with salt and pepper. Roast in the hot clarified butter for three minutes on each side. Transfer to the preheated platter and reheat in the stove at eighty degrees for about thirty minutes.
Melt the gravy with calvados and white wine and make it half. Add the crème fraîche. Add the onions and mushrooms, season and continue to cook until the sauce thickens slightly.
Pluck the chervil leaves from the twigs. Pour the hot sauce over the veal chops form. Sprinkle with chervil leaves.
By the way: Did you know that clarified butter is obtained by extracting water, milk protein and lactose from butter?