Soak the dried mushrooms in the boiling water. Meanwhile, heat the oil in a deep frying pan over a medium heat. Add the onion and cook for 3 minutes, then add the garlic and stir for a further 2 minutes until the onion is softened.
Add the rice to the pan, stir for about 1 minute, then add the wine or vermouth and cook briskly, stirring, until almost all of it has evaporated.
Strain the dried mushrooms, reserving the soaking liquid. Stir the fresh mushrooms into the rice, then start adding the stock. Only a ladleful at a time, making sure each is almost completely absorbed before adding the next. (Stir frequently to produce a creamy texture.) When all the stock has been absorbed, gradually add the mushroom soaking liquid and continue cooking until the rice is tender.
Stir in the soaked porcini mushrooms and the butter, cover and remove from the heat. Stand for 5 minutes, season to taste, then serve sprinkled with Parmesan cheese and parsley.
Nutrients per serving: 383 calories, 13.5 g protein, 22 g fat (6.5 g saturated fat), 85 g carbohydrate (3.5 g fibre)