1.Saute onion and mushrooms in oil and butter until soft.
2. Stir in rice and cook till transparent, add wine if it gets dry.
3. stir in 1 ladle of stock. Stir well, cover and simmer gently for several minutes or till rice looks dry.
4. Add more stock, stir,cover and keep repeating this process till rice is just cooked (about 25 minutes).
5. Taste and add a little salt.
6. Now remove from heat and stir in parmesan, parsley, extra butter if using and pepper to taste.