Method

1. Make the gratin first of all. Set the oven to 200°C/gas 6. Lightly butter a gratin dish using a little of the butter.

2. Heat the cream with the rosemary and anchovy oil from the tin, and bring to scalding point. Turn off the heat and allow the flavours to infuse for 15 minutes.

3. Peel and grate the potatoes and arrange layers of potato, chopped anchovy and sliced onion in the gratin dish. Pour over a little hot cream and then repeat layers, finishing with a layer of potatoes. Pour over half the remaining cream, and sprinkle with breadcrumbs.

4. Place in the oven and bake for 35 minutes. Pour over the remaining cream and dot with the remaining butter. Sprinkle with the pepper. Bake for a further 20 minutes until bubbling and golden.

5. Season the steaks with salt. Cover one side with a thin layer of finely crushed pepper.

6. Heat the oil in a frying pan. When hot, fry the steaks for a couple of minutes on each side for medium rare - or cook for longer if preferred.

7. Add a splash of brandy and flame. Remove the steak and keep warm. Reduce the mixture by half and fold in the butter and a splash of stock and pour over the top of the steak.

8. Allow the steak to rest for a few minutes and serve with the gratin.