How to Make It
In a medium saucepan, heat the chicken stock until just boiling; keep warm. Melt the butter in a large nonreactive saucepan. Add the onion and cook over moderate heat, stirring, until translucent, about 3 minutes. Add the rice and stir to coat. Add the wine and cook, stirring, until absorbed, about 3 minutes.
Add 1/2 cup of the hot chicken stock to the rice and stir constantly over moderate heat until the liquid is completely absorbed, about 3 minutes. Continue adding the stock, 1/2 cup at a time, stirring constantly until absorbed before adding more. When half of the stock has been added, stir in the prosciutto, peas, rosemary and thyme and continue cooking. The rice is done when it's tender but still slightly firm to the bite. Remove from the heat, stir in the cream and 1/4 cup of the Parmesan and season with salt and pepper. Spread the risotto on a baking sheet and let cool. Cover and refrigerate until chilled, for at least 2 hours or up to 1 day.
Roll the risotto into 1-inch balls. Roll each ball in the flour, then dip in the beaten eggs and coat with the bread crumbs.
In a deep fryer fitted with a basket, heat 4 inches of vegetable oil to 360°. Working in batches of 8, fry the risotto balls until golden, about 45 seconds; if they have been frozen, fry for about 4 minutes. Transfer to paper towels to drain. While hot, roll the risotto balls in the remaining 2 cups Parmesan to lightly coat them. Transfer to platters and serve immediately.