Add all but 1 tablespoon of the fennel fronds, the bread crumbs, and eggs to the pork mixture and mix gently. Spread the mixture over the pork loin. Roll it up, starting from a long side, like a jelly roll, and tie with butcher's twine.☞ TESTER TIP: To prevent the filling from squishing out the ends, poke several long skewers through the porchetta near both ends to help close them before tying with twine.