- 2 cloves garlic, peeled and divided
- 2 ½ cups baby arugula, plus more for garnish if desired
- ¼ cup finely shredded Pecorino Romano cheese
- 2 tablespoons pine nuts or pepitas
- 2 tablespoons extra-virgin olive oil
- 1/8 plus ¼ teaspoon salt, divided
- 1 2.3-pound trimmed boneless pork loin, only a thin fat cap left on.
- 2 teaspoons peanut or grape-seed or peanut oil
- 2 teaspoons Dijon mustard
- 1 teaspoon fennel seeds
- ½ teaspoon freshly ground pepper
- Make Pesto: With motor running drop 1 clove garlic through feed tube of food processor and let mince. Add 2 ½ cups arugula, Pecorino Romano, pine nuts, olive oil and 1/8 teaspoon salt and process, scraping down the sides as necessary, until finely ground and smooth.
- Butterfly pork: Lay pork on work surface end facing you. Slice pork in a spiral pattern to butterfly it open to about 2/3-inch thick. First, hold knife horizontally, and slice along the side of the length of the loin cutting under the fat cap by about 2/3 of an inch to an inch thick. As you reach about 2/3 inch thick on the other side, turn your knife down toward the cutting board and continue cutting in a spiral until into the center. Open the pork out and lay a sheet of plastic wrap over the pork. Pound meat to an even thickness with the smooth side of a meat mallet. About ½ to 2/3 inch thick only.
- Preheat oven to 400 degrees F.
- Stuff and roll pork: Remove plastic wrap and spread pesto over the pork. Roll the pork up into a log lengthwise. Tie in several places to hold it firmly back into a loin shape.
- Make garlic and fennel rub: Mince and mash the remaining clove of garlic and fennel seeds with the remaining ¼ teaspoon salt in a mortar and pestle or with a chef knife until it forms a paste. Transfer the paste to a small dish. Stir in Dijon.
- Heat grape-seed oil in a large oven-proof skillet over high heat until shimmering but not smoking. Sear top (fat cap) and sides of the roast until browned, 4 to 5 minutes. Remove from heat, place bottom-side-down and smear the garlic paste all over the top and sides of the roast.
- Transfer the skillet to the oven and cook until an instant read thermometer inserted into the center of the roast reaches 138 degrees, 40 to 45 minutes. Remove from the skillet, and allow to rest on a carving board, 10 to 15 minutes. Internal temperature of roast will continue to rise as the pork rests.Remove twine and slice to serve, garnishing with extra arugula if desired.
- Serving Size: 4 ounces