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
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
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!