Season the strips of prosciutto fat with salt and pepper and use them to lard the beef. Stick the cloves in the meat. Combine the remaining fat and the rind in a pan that just holds the meat. Add the butter, scallion, celery, carrot, parsley bundle and garlic and cook over high heat for a few minutes, until the vegetables begin to brown. Add the meat and brown it over high heat. Add the wine and let it evaporate. Meanwhile, dissolve the tomato paste in 1/2 cup boiling water and add it to the pot. Add enough additional boiling water so that the meat is just barely covered. Cover and simmer for 30 to 45 minutes, or until the meat is very tender. Remove the meat and set aside. Reduce the sauce for another 30 minutes, uncovered.