Beef shin ragu

Toss the beef shin with the flour, mustard powder and some seasoning in a large bowl until evenly coated. Heat the oil in a casserole over a medium-high heat and fry the meat in batches until golden brown all over. Remove to a plate while you fry the rest of the beef shin.

Heat the oven to 160C/fan 140C/gas 3. Put the porcini mushrooms in a heatproof bowl, cover with 250ml of just-boiled water and leave to soak.

Once all the meat is browned, tip the onions and celery into the pan with a splash more oil, if needed. Fry for 10 minutes until the veg has softened, scraping up any browned bits from the bottom of the pan. Stir in the tomato purée, cook for 2 minutes, then return the beef to the pan along with the stout. Bring to the boil, then add the stock and herbs. Bring back to a simmer and season well. Add the mushrooms and soaking liquid (leaving the last bit of liquid in the bowl, as this may contain grit) so the meat is covered, adding a little more stock or water if needed. Cover and cook in the oven for 3 hours until the meat is tender. Remove the lid for the final 30 minutes to thicken the sauce, if needed.

Stir in the walnuts and check for seasoning, adding 1 tsp of the vinegar and 2-3 tsp of brown sugar to balance the bitterness in the stout, as needed. Cool completely, transfer to a freezer-proof container and freeze for up to three months. To reheat, defrost completely in the fridge overnight, then reheat in a pan over a low heat until piping hot.

Heat the oven to 200C/fan 180C/gas 6. Put the bones on a baking tray, cut-side up, and season. Roast for 10-12 minutes until the marrow looks melty and lightly golden, but it shouldn’t be completely melting out onto the tray. Toss the kale with the olive oil and some salt and pepper. Tip onto a tray in a single layer and roast for 10-12 minutes, tossing halfway through, until crisp enough to crumble when handled. Set both aside.

To make the polenta, bring 1 litre of water to a simmer in a large pan with 2 tsp of sea salt flakes. Whisking constantly, scatter the polenta into the water in a thin stream. Once all the polenta has been added and the mixture starts to thicken, use a wooden spoon or spatula to beat the polenta for 2-3 minutes over a low heat until soft and creamy. Beat in the butter and parmesan. Scrape the roasted bone marrow from the bone and add this to the polenta. Check for seasoning. When ready, it should be thick enough to come away from the sides of the pan as you stir, yet thin enough to drop off the spoon when held up. Add a splash more water if needed. Spoon the soft polenta over six plates and top with the beef shin ragu. Add a spoon of the kale to serve.