Method
1
Rinse and soak the porcini
Give the 25 g dried porcini a quick, thorough rinse under running water to remove surface dust. Put them in a clean transparent bowl with 400 ml warm water and soak for about 25 minutes, until fully soft throughout. If thicker slices still have a firm centre, soak longer until soft. Prepare the onion, garlic, fresh mushrooms and cheese while they soak. Lift out the porcini, rinse again in clean water and cut any large pieces into bite-size slices. Soaking restores the dried mushrooms’ texture; it does not replace cooking. Cook promptly once soft. If prolonged soaking is needed, switch to cold water and continue in the fridge rather than leaving the mushrooms at room temperature.

2
Filter the soaking liquid
Leave the soaking liquid to settle briefly. Slowly pour it through a paper coffee filter set in a sieve over a clean bowl. Stop before the gritty sediment at the bottom reaches the filter, and discard the sediment and the remaining gritty liquid. Keep the clear filtered liquid; never add unfiltered gritty water to the risotto.

3
Pre-simmer the porcini
Put the filtered liquid, 800 ml vegetable stock and rehydrated porcini in a saucepan. Bring to the boil, then cover loosely and simmer gently for 25 minutes. Top up with hot water if needed so you have about 1.2 litres of cooking liquid. Lift out the porcini with a slotted spoon and keep the broth hot. The porcini will cook for a further 18–22 minutes with the rice, giving 43–47 minutes of cooking in total; soaking time does not count.
4
Brown the fresh mushrooms
During the final 10 minutes of the pre-simmer, heat 10 ml olive oil in a wide heavy saucepan or deep frying pan. Add the sliced fresh mushrooms and cook over a medium-high heat for 6–8 minutes, stirring occasionally, until their released liquid has evaporated and the edges are lightly browned. Transfer to a plate.
5
Soften the onion and toast the rice
Lower the heat to medium. In the same pan, heat the remaining 10 ml olive oil. Add the onion and cook for 4–5 minutes until softened, then stir in the garlic for 30 seconds. Add the dry risotto rice and stir for 1 minute. Return the browned fresh mushrooms and add the pre-simmered porcini.
6
Add hot broth a little at a time
Add about 200 ml hot mushroom broth and keep the pan at a gentle simmer. Stir frequently. As the liquid is absorbed, add another 100–150 ml and repeat, keeping the rice moist rather than letting it fry dry. Cook for about 18–22 minutes after the first broth addition, until the rice is plump and tender with a slight bite and no hard chalky centre. Depending on the pan and rice, you may use around 1–1.2 litres of broth; add a little hot water if it runs out. The finished mixture should spread slowly when spooned onto a plate.

7
Finish and serve
Take off the heat. Stir in the butter and 30 g grated Parmesan. Add a splash of hot broth or water if it has become stiff. Taste before adding salt, then add black pepper. Rest for 1 minute, divide among four shallow bowls and finish with the remaining 10 g Parmesan and optional parsley. Serve immediately.
Cooking tips
- Use Arborio or Carnaroli risotto rice without rinsing: its surface starch helps create a creamy texture. Long-grain rice gives a different result.
- Use 25 g from the 100 g pack, not the whole pack. Reseal the remaining dried porcini and store as directed on the label.
- The specified porcini are cooked for 43–47 minutes altogether. Follow the directions on your actual packet if the batch instructions differ.
- This recipe uses Parmesan, which is made with animal rennet. For a vegetarian version, use vegetable stock and replace the Parmesan with a hard cheese explicitly labelled suitable for vegetarians.
Allergens
Contains milk from butter and Parmesan. Check vegetable-stock labels for celery, gluten-containing cereals or other allergens. The porcini pack states it is packed in a facility handling peanuts, tree nuts, sesame and soya; consult the actual pack when serving someone with an allergy.
Storage and reheating
Best served freshly cooked. Divide leftovers into shallow small portions, cool quickly, ideally within 1 hour, then refrigerate and consume within 24 hours. Reheat only once until steaming hot throughout. Do not leave it in the warm pan to cool.