In a food processor, process the pesto ingredients with a good amount of olive oil. I cut my pork belly and loin each in half to make 2 more manageable porchettas instead of one huge one. It also made everything fit better. Lay out the pork belly onto the counter and brush the herb mixture onto the pork. Place the loin on top of the belly and roll the belly around the loin. Use butchers twine to secure the pork (use this video as a guide if you don't know how to tie a roast). Roast at 325 for about 3 hours until you get an internal temp of 150 at the deepest center of the porchetta. Cool fully and slice thin for sandwiches!