Preheat oven to 425 degrees. In an ovenproof saucepan or Dutch oven, heat oil over medium-high heat. Add the onion and cook, stirring, until translucent, 2 to 3 minutes. Add the rice and cook, stirring to coat the grains with oil, about 1 minute.
Stir in the wine and cook until it has completely evaporated, about 1 minute. Stir in 1 1/2 cups water, the stock, salt, and pepper. Bring to a boil. Cover, transfer to the oven, and bake, until most of the liquid has been absorbed by the rice, 20 to 25 minutes.
Remove from oven. Stir in 1/2 to 3/4 cup water (the consistency of the risotto should be creamy), the butter, cheese, and parsley. Serve immediately.