First up soak bones in ice cold water for 48 hrs to draw out the blood and impurities!

Drain bones and tray up

Scrape the split side to remove any bone dust

Like this

Place in a tray

Cook for 18 minutes on 200c

Get your shallot, parsley, capers and cornichons

Chop it all up and slice your shallot into rings

Like this

Add some EVOO

Add some cider vinegar

Toast some bread

Scoop out some marrow

Spread on toast

Top with dressing, sprinkle with salt and enjoy!