1 Preheat the oven to 180°C, gas mark 4. Put the porcini in a small bowl, cover with 150ml boiling water and leave to soak.
2 Season the beef well with salt and pepper. Heat a flameproof casserole, then add 2 tablespoons of the olive oil. When the oil is hot add the beef (in batches) and sear on all sides. As each batch is browned, remove and set aside.
3 Add the remaining olive oil to the casserole with the celery, garlic, onions and rosemary. Cook for about 5 minutes until the vegetables are softened.
4 Remove the soaked mushrooms and add to the pan. Strain the soaking liquid through a fine sieve (to ensure there is no grit) into the casserole. Boil to reduce the liquid by half, then add the chopped tomatoes and wine. Bring to a simmer.
5 Return the beef to the casserole. Cover with greaseproof paper and place in the oven to cook for 2 hours, until the stew is thick and the meat tender.
6 For the polenta, bring the water to a simmer, add salt, whisk in the polenta and cook, stirring, on a low heat for 10 minutes or until the polenta comes away from the sides of the pan. Add the butter and cheese and stir vigorously.
7 Check the seasoning before serving hot, with the wet polenta.