Cut the veal kidneys into eight slices
Brush them with mustard
Peel and wash the potatoes
Cut them to the size of a 5 cm slice
Brown the potatoes with 40 g of butter, then moisten with the chicken stock, let reduce, set aside.
Prepare the Béarnaise sauce
Gently fry the kidney slices in 60 g of butter, season with pepper, drain on paper towel.
Arrange the slices of mustarded kidneys on a plate accompanied by the potatoes.
Cover and serve the rest of the sauce in a sauce boat.
