Pernil is a Puerto Rican dish of heavily seasoned, long-cooked pork with supremely crispy skin. We use a bone-in pork picnic shoulder, which is more widely available than a fresh ham, and rub it with a flavorful herb and spice paste called a sofrito. We start cooking the pork skin side down in a roasting pan—first covered, to create steam, and then uncovered. We move the roast to a V-rack with the skin side up to start drying out the skin, and we finally crank up the heat and finish the roast at 500 degrees for just long enough to render the skin a deep mahogany brown as well as crispy. A quick sauce of pan drippings, cilantro, and lime finish the dish.
1. Pulse 1 cup cilantro, onion, salt, oil, garlic, pepper, oregano, and cumin in food processor until finely ground, about 15 pulses, scraping down sides of bowl as needed. Pat pork dry with paper towels and rub sofrito all over. Wrap pork in plastic wrap and refrigerate for at least 12 hours or up to 24 hours.
2. Adjust oven rack to lower-middle position and heat oven to 450 degrees. Pour 8 cups water in large roasting pan. Unwrap pork and place skin side down in pan. Cover pan with tightly crimped aluminum foil and roast for 90 minutes. Remove foil, reduce oven temperature to 375 degrees, and continue to roast for 2 1/2 hours.
3. Remove pan from oven. Spray V-rack with vegetable oil spray. Gently slide metal spatula under pork to release skin from pan. Using folded dish towels, grasp ends of pork and transfer to V-rack, skin side up. Wipe skin dry with paper towels. Place V-rack with pork in roasting pan. If pan looks dry, add 1 cup water. Return to oven and roast until pork registers 195 degrees, about 1 hour. (Add water as needed to keep bottom of pan from drying out.)
4. Line rimmed baking sheet with foil. Remove pan from oven. Transfer V-rack and pork to prepared sheet and return to oven. Immediately increase oven temperature to 500 degrees. Cook until pork skin is well browned and crispy (when tapped lightly with tongs, skin will sound hollow), 15 to 30 minutes, rotating sheet halfway through cooking. Transfer pork to carving board and let rest for 30 minutes.
5. Meanwhile, pour juices from pan into fat separator. Let liquid settle for 5 minutes, then pour off 1 cup defatted juices into large bowl. (If juices measure less than 1 cup, make up difference with water.) Whisk remaining 1/2 cup cilantro and lime zest and juice into bowl.
6. Remove crispy skin from pork in 1 large piece. Coarsely chop skin into bite-size pieces and set aside. Trim and discard excess fat from pork. Remove pork from bone and chop coarse. Transfer pork to bowl with cilantro-lime sauce and toss to combine. Serve pork, with crispy skin on side.