Place 1 1/2 cups of the peas in a blender along with the 1/2 cup of reserved broth and puree until smooth. Set aside until ready to use and reserve the remaining cup of whole peas for the very end.

Heat the olive oil in a large, deep skillet over medium heat. Add the onions and cook for 5 minutes, until soft. Add the rice and stir to coat the rice grains with oil. Add the wine and boil until most of the liquid has evaporated.

Add 1 cup of the hot broth and the salt. Stir gently until most of the broth has been absorbed. Add the remaining cup of stock, repeating the process. After 10 to 15 minutes the rice should be creamy but still very slightly chewy. If the rice seems too dry, a little more broth. Stir in the butter and Parmesan. Stir in the basil, pureed peas and the reserved cup of whole peas. Heat through and add salt to taste. Sprinkle with the pancetta and garnish with a sprig of basil. Serve immediately.