How to Make It
In a large pot, add the rosemary, bay leaves, garlic, juniper, peppercorns, fennel seeds, crushed red pepper and 1 gallon of water. Bring to a simmer over high heat, cover and cook for 10 minutes. Add the salt, sugar and honey and stir until dissolved.
Pour the brine into a large roasting pan and let cool completely. Add the pork belly to the brine, skin side up. Cover with plastic wrap and refrigerate overnight.
In a small skillet, toast the fennel seeds, juniper berries and black peppercorns over moderate heat until they are fragrant, about 1 minute. Let cool, then grind to a powder in a spice grinder. Transfer the spice blend to a small bowl and stir in the nutmeg, crushed red pepper, rosemary and garlic.
Drain the pork belly and pat dry, then pick off any spices. Turn the belly skin side down and rub the meaty side with the spice blend. Transfer the pork belly to the roasting pan, skin side up, and pierce the skin all over with the tip of a knife. Refrigerate the pork uncovered overnight.
Preheat the oven to 400° and position a rack in the lower third. Set the pork belly skin side down on a work surface. Roll up the belly lengthwise to form a tight cylinder and tie tightly at 2-inch intervals with kitchen twine.
Return the pork to the pan and roast for 1 hour. Lower the heat to 300° and roast for 2 hours and 15 minutes longer, until the skin is deep brown and crisp and an instant-read thermometer inserted in the center registers 170°. Transfer the porchetta to a cutting board and let rest for 20 minutes. Remove the twine and slice the porchetta 1/2 inch thick, using a serrated knife to cut through the skin. Serve with roasted potatoes.
The porchetta can be prepared through Step 5 and refrigerated overnight.
Because pork belly can be a very fatty cut, be sure to ask your butcher for one that is very meaty, at least 50 percent lean.