How to Make It
In a medium enameled cast-iron casserole, heat the olive oil until shimmering. Add the onion and cook over low heat until softened, about 7 minutes. Add the pancetta and 2 tablespoons of the parsley and cook for 5 minutes. Add the stock, peas and rice and bring to a simmer over moderately high heat.
Cover and cook over moderately low heat until the rice is tender and most of the liquid is absorbed, about 20 minutes. Stir in the 1 cup of Parmesan, the butter and the remaining 2 tablespoons of parsley and season with salt and pepper. Ladle the rice and peas into shallow bowls and serve at once, passing more Parmesan at the table.