1 cup apple cider
1/2 cup cider vinegar
3/4 cup packed light brown sugar
1 large shallot, peeled, thinly sliced
1 1/2 cups dried apples (packed)
1/2 cup dried cranberries
1 Tbsp grated fresh ginger
1 Tbsp yellow mustard seeds
1/2 teaspoon ground allspice
1/8 to 1/4 teaspoon cayenne pepper
2 1/2 pound boneless center-cut pork loin roast (short and wide - about 7-8 inches long and 4-5 inches wide)
Kosher salt and freshly ground black pepper
1 Chill the roast to make it easier to cut: Before starting on the pork, put the pork roast in the freezer for 30 minutes to make it easier to cut. While the pork is chilling, you can make the filling.
2 Make the filling and glaze: Bring all the filling ingredients to simmer in medium saucepan over medium-high heat. Cover, reduce heat to low, and cook until apples are very soft, about 20 minutes.
Strain through a fine-mesh sieve, reserving the liquid. Use a rubber spatula to press against the apple mixture in the sieve to extract as much liquid out as possible.
Return liquid to saucepan and simmer over medium-high heat until reduced to 1/2 cup, about 5 minutes. Remove from heat, set aside and reserve this liquid for use as a glaze.
Pulse apple mixture in food processor, about fifteen 1-second pulses. Set aside.
3 Preheat oven to 350°F or prepare your grill for indirect heat.
4 Butterfly the roast: You will be "double-butterflying" the pork roast. Lay the roast down, fat side up. Insert the knife into the roast 1/2-inch horizontally from the bottom of the roast, along the long side of the roast.
Make a long cut along the bottom of the roast, stopping 1/2 inch before the edge of the roast. You might find it easier to handle by starting at a corner of the roast.
5 Spread filling on roast and roll up tightly: Season the inside of the roast well with salt and pepper. Spread out the filling on the roast, leaving a 1/2-inch border from the edges.
Starting with the short side of the roast, roll it up very tightly. Secure with kitchen twine at 1-inch intervals. Season the outside of the roast generously with salt and pepper.
6 Roast in oven: Place roast on a rack in a roasting pan, place in oven, on the middle rack.
Cook for 45 to 60 minutes, until the internal temperature of the roast is 130 to 135 degrees F.
Brush with half of the glaze and cook for 5 minutes longer. Remove the roast from the oven or grill. Place it on a cutting board. Tent it with foil to rest and keep warm for 15 minutes before slicing.
7 Slice: Slice into 1/2-inch wide pieces, removing the cooking twine as you cut the roast. Serve with remaining glaze.