1. On a large frying pan heat 1/2 tbsp. olive oil over a low heat, add garlic and chestnut mushrooms and cook them until soft remove from the pan and set aside.
2. Heat the remaining olive oil and add onion and rice, stir the ingredients and pour in 1/4 of the vegetable stock, stir it again and cover the pan with the lid.
3. When the mixture becomes a bit thicker add porcini mushrooms and another 1/4 of the stock. Simmer until more liquid has been absorbed and continue adding more stock until the mixture is tender.
4. Add cooked mushrooms and mix them with the risotto.