There are several types of risotto rice. The easiest to find is
arborio; it needs the least cooking time and tends to break down
easily. We've used carnaroli here, which is worth seeking out - it
holds its shape nicely.
20 gm dried porcini mushrooms80 gm butter, coarsely chopped2 tbsp olive oil300 gm Swiss brown mushrooms, thickly sliced5-6sage leaves, coarsely chopped1small onion, finely chopped400 gm risotto rice, preferably carnaroli125 ml (½ cup) dry white wine85 gm (1/3 cup) mascarpone, plus extra to serve (optional)35 gm (1/3 cup)finely grated parmesan, plus extra to serve
Soak porcini in a bowl with 700ml boiling water for 10 minutes to soften. Drain, reserving stock. Finely chop mushrooms and reserve. Keep stock warm.
Meanwhile, heat half the butter and half the oil in a saucepan over high heat, add fresh mushrooms and sage and sauté until tender and golden brown (3-5 minutes). Set aside. Add remaining butter and oil to pan along with onion and sauté until golden brown (4-5 minutes). Add rice and stir to coat in oil, then add wine and simmer until evaporated (1 minute). Add reserved stock a ladleful at a time, stirring continuously between additions until most is absorbed before adding the next, until rice is al dente and creamy (13-15 minutes; you may not need all the stock). Season to taste, stir in mascarpone, parmesan and three-quarters of both mushrooms, then serve risotto topped with remaining mushrooms and extra grated parmesan.