Render chorizo in a saucepan that is large enough for risotto. Remove chorizo but leave fat in the pan. Add the olive oil and cook the onions until translucent.
Add the rice. Stir for about 3 to 4 minutes. Add the wine and cook down. Start adding the stock, two ounces at a time, keeping the heat on low.
Stir constantly with a wooden spoon until cooked, should be al dente. Finish with butter, cheese, peas, and chorizo.