The joint was from Hartes Irish Butchers in Harlesden. Best value butchers in London (that’s a 1.3kg single forerib for 12 quid).
Marinate in a roasting bag full of oyster sauce and garlic powder overnight in the fridge.
Take it out of the fridge in the morning when you wake up and bring it up to room temp. I left it in the bedroom because our kitchen is freezing.
Pre-heat your oven to 200.
Loads of sea salt on each side of the rib then sear it in a smoking hot frying pan for 3 minutes per side (you think this’ll burn it but it doesnt, trust me) then stick it on the top shelf of the oven for 15 minutes for rare. If you’re weird and like well cooked beef do it for a bit longer but we’re talking minutes here. 25 minutes will be past well done for a 2 inch joint. You have to rest the meat and because there’s a hot bone in it, it’ll keep cooking for a while.
Take it out of the oven, double wrap it in foil and keep it warm (back to the bedroom).
It’s been trial-and-error but I’ve fucking nailed this now and the above is the way to do perfect, rare, CdB.
Make sure the butcher cuts the rib “large”, meaning there’s the same amount of meat on each side of the rib you buy. Some will cut it “small” meaning you only have meat on one side of the bone. That still works but I like to marinate my meat, rather than half a bone.