How to Make It
In a deep 12-inch skillet, heat the olive oil until shimmering. Add the pancetta slices and cook over moderate heat, turning occasionally, until browned and crisp, about 6 minutes. Transfer the pancetta to a work surface and chop finely. Reserve the skillet and fat.
In a large bowl, mix the pancetta with the eggs, pecorino cheese, bread crumbs, 6 tablespoons of the parsley and half of the minced garlic. Season with 1/2 teaspoon each of salt and pepper.
Working with 1 piece of lamb at a time, place the meat on a work surface between two sheets of plastic wrap and pound it into a roughly 4-by-6-inch rectangle, 1/4 inch thick. Spoon the filling onto each pounded piece of lamb, leaving a 1-inch border on one of the shorter sides. Starting on the shorter end, press the filling to compact it slightly and roll the lamb into a tight cylinder. Tuck in any loose flaps of lamb and tie up the rolls with kitchen string.
Set the skillet over moderately high heat until the fat shimmers. Add the lamb rolls in a single layer and cook, turning occasionally, until browned all over, 10 to 12 minutes. Transfer the lamb rolls to a large plate. Add the onion to the skillet and cook over moderate heat, stirring, until softened, about 8 minutes. Add the remaining garlic and cook until fragrant. Add the tomato paste and cook, stirring, for 1 minute. Pour in the wine and simmer until slightly reduced, scraping up any browned bits stuck to the bottom of the skillet, about 3 minutes. Add the water, chopped tomatoes, crushed red pepper and a pinch of salt.
Return the lamb rolls and any accumulated juices to the skillet and bring to a boil. Cover tightly and simmer over moderately low heat until the lamb is tender, about 1 1/2 hours. Transfer the lamb to a deep platter, cover with foil and keep warm.
Boil the sauce over high heat, stirring, until slightly thickened, about 5 minutes. Pour over the lamb rolls, sprinkle with the remaining parsley and serve.