Cut open the lamb and pound it out with a meat mallet to 1-inch thickness, or have your butcher do this for you. Season with salt and pepper on both sides.
In a medium bowl, combine the bread crumbs, chopped garlic, and chopped parsley, and mix well. Spread this mixture in an even layer over the meat. Distribute the prosciutto over the meat in an even layer, then place the egg wedges in one line down the center of the meat. Sprinkle the cheese over the meat in one layer. Roll the meat up and tie it tightly with butcher's twine.
In a large dutch oven, heat the olive oil over medium-high heat. Add the meat and brown it deeply on all sides. Add the wine to the pan and let it evaporate. Add the onion, carrot, celery, whole parsley, garlic clove, and bay leaves and cook 10 minutes more, then add the tomato paste and tomatoes. Cook, covered, at a simmer over low heat for 2 hours. Turn the meat once or twice and add more wine or water if necessary to keep it from drying out. Once the meat is done, remove, and let rest 15 minutes before carving.
Bring 6 quarts of water to a boil and add 2 tablespoons salt.
Strain the pan juices and return to the roasting pan, discarding the solids. Bring the juices to a boil over medium-high heat and stir to dislodge browned bits from the bottom of the pan. Adjust the seasoning with salt and pepper, if necessary, and keep hot.
Cook the ziti in the boiling water according to the package directions, until tender yet al dente. Drain the pasta and add to the sauce, adding a splash of cooking water if necessary to keep the sauce from getting too "tight".
Serve the pasta in heated pasta bowls, topped with grated Parmigiano-Reggiano, and serve the sliced lamb alongside or as a second course.