Rognons de Veau à la Bordelaise

‘Bordeaux likes cèpes as cèpes love oil’, runs a local catch-phrase; wild mushrooms certainly appear in a remarkable number of Bordelais recipes. They are usually fried in oil with a touch of garlic as here, but some cooks prefer olive oil or butter. Excess liquid is always a problem with cèpes, so be sure to use a high heat to sauté them. Use vegetable oil when making the coulis and omit the sugar and basil. In this recipe the cèpes are served apart from the kidneys, so steak or another me