This pie came about because I wanted to make something like the cow pies (Americans stop sniggering) that cartoon character Desperate Dan lives on. His pies have a pair of cow horns sticking out of the top but I can't get those. But the idea of three marrowbones sticking out of the top is borrowed from Calum Franklin's great book, The Pie Room. And, a confession - I normally insist that a pie must have pastry top and bottom. This only has pastry on top, but it's still fabulous.
Oil for sautéeing. 3 lengths of marrow bone, about 15cm (6 inches).