Bring stock to a gentle simmer . Turn down, cover and keep warm.
Saute the onion and garlic in the olive oil and butter until soft.
Add rice and stir , saute over medium heat until the outside edge of rice kernels begins to turn translucent.
Add wine, shake pan to keep rice from sticking to each other.
You will be adding stock repeatedly over 18-20 minutes. For the first 10 minutes you will add in1/2 cup increments , after which you will add the remainder in 1/3 or 1/4 cup increments. The signal to add the next increment is when "the wave" of rice created with the shaking of the pan begins to give way to the rice sticking to each other.
Risottos are of many varieties. Generally they include mushrooms, or vegetables or meats which are prepared in a separate skillet. These defining ingredients are added to the risotto generally in the last 5 minutes of cooking.
After 18-20 minutes (taste), take pan off heat ,swirl in 3 tbs of butter , the cup of parmigiano and 1/4 cup of stock ,cover and let sit for 5 minutes.
Serve.
