To serve, pile the potatoes onto serving plates and place one steak alongside each portion. Spoon over the sauce bordelaise.

Set these aside for later and add the beef stock to the liquid fat in the pan to warm through. Once the wine has reduced, pour the warm stock and bone marrow mixture into the wine pan and bring to ...

The onion puree, caramelised onions and bordelaise sauce can be made ahead ... 2 onions, peeled and thinly sliced 25g butter, preferably unsalted 100ml cream Pinch salt and freshly ground white ...