Soak the bone marrow in cold water, in the fridge, for 24 hours. Drain and blend in a blender.
Put the beef consommé, red wine, bouquet garni and garlic in a large saucepan and bring to the boil.
Meanwhile, heat the oil in a frying pan over a medium heat and sear the beef all over. Lower it into the consommé stock and poach at a simmer for 5–8 minutes. Remove the beef from the pan and set aside to rest.
Parboil the potatoes, leave to cool and then thickly slice them. Melt the butter in a sauté pan over a medium heat. Add the potatoes and cook for 7–10 minutes, or until starting to colour on both sides.
To make the vinaigrette, put the shallot and wine in a saucepan over a medium heat. Bring to the boil and simmer until the liquid has reduced to a tablespoon.
Put the remaining vinaigrette ingredients in a bowl, then whisk in the wine reduction.
To make the hollandaise, heat a frying pan until hot, add the butter and cook until it turns a nut-brown colour. Set aside to cool to room temperature.
Put the egg yolks and lemon juice in a food processor and gradually add the browned butter, bone marrow and mustard. Season with salt and pepper.
To serve, dress the potatoes in the vinaigrette and scatter over a large serving platter. Slice the beef and place on top, with the hollandaise spooned over.