Carpetbag steak with potato cake and greens

By Matt Tebbutt From Saturday Kitchen Ingredients For the carpetbag steak 6 fresh oysters, shucked 1 lemon, juice only 2 thick, centre-cut fillets of beef, about 200g/7oz 3 strips pancetta or lardo 50g/1¾oz unsalted butter 200ml/7fl oz chicken stock 100ml/3½fl oz Madeira 20g/¾oz plain flour …