In a large sauté pan, add the onion, butter and oil and simmer over medium heat.
After the onion has become translucent, add the rice and sauté for several minutes. Allow the rice to coat with the oil mixture for several minutes.
Add the mushrooms and parsley and cook for several minutes longer.
Add the wine and cook off for an additional few minutes.
When the wine has dried up, add one cup of stock to the rice. Allow the broth to absorb before adding the next cup of stock.
Continue the process of adding one cup of stock at a time until the rice is fully cooked. This will take about 20-25 minutes.
When fully cooked, remove from heat and stir in the grated Parmigiano cheese. Taste and add salt, if needed. Serve hot.