600g/1Ib 5oz russet potatoes, grated
1 tsp finely chopped rosemary leaves
1 tsp finely chopped thyme leaves
1 tbsp plain flour
sea salt and black pepper
2 tbsp rapeseed oil, for frying
50驳/1戮辞锄 butter
50驳/1戮辞锄 unsalted butter, for frying
4 free-range eggs
1 free-range egg, lightly beaten
4 x 175g/6oz onglet steaks, trimmed
4 marrow bones, halved horizontally