Place the beef shin pieces in a bowl and cover with red wine. Cover the bowl with cling film and chill in the fridge overnight. The next day, remove the beef from the red wine and pat dry with kitchen paper. Reserve the red wine.
Preheat the oven to 150C/130C Fan/Gas 2.
Heat a tablespoon of oil in a flameproof casserole over a medium heat. Fry the beef shin pieces for a few seconds on all sides, or until nicely browned all over. Remove from the pan and set aside.
Add the carrot, celery and onion to the casserole and fry gently for 4-5 minutes, stirring regularly, until softened. Add the bay leaves and star anise, then lay the browned meat on top of the vegetables. Sprinkle over the salt and pour in the reserved red wine. Bring the mixture the boil.
Add the chicken stock and return the mixture to the boil. Cover the casserole with a lid and transfer to the oven. Cook for 3½-4 hours, or until the beef shins are very tender.
Remove the beef shins from the casserole. Pull the meat off the bone and break into flakes. Extract the marrow from the bones. Set aside and keep warm. Strain the stock from the casserole through a fine sieve and keep warm.
For the risotto, heat the oil and butter in a saucepan over a medium heat. Add the onion and garlic and fry for 3-4 minutes, or until soft but not coloured.
Stir in the risotto rice and cook for 1-2 minutes, or until coated in the fat and slightly translucent.
Add the warm beef stock a ladleful at a time, stirring well after each addition and allowing almost all of the liquid to be absorbed before adding the next ladleful.
Continue to add the stock until the rice is just tender (you may not need to use all the beef stock).
Remove the risotto from the heat and stir in the flaked meat, a knob of butter, the blue cheese and the thyme leaves. Add the bone marrow, to taste and stir well until the butter and cheese have melted, then serve in shallow bowls.