Coarse salt (sea or kosher) and freshly ground black pepper
3 tablespoons Dijon mustard
6 ounces lean pastrami
1 cup sauerkraut (not canned)
6 ounces gruyere cheese
3 tablespoons chopped fresh chives
4 strips artisinal bacon
Vegetable oil for oiling the grill grate
1 cup mayonnaise
1/3 cup chili sauce or ketchup
1/4 cup sweet pickle relish
Directions
:::russian dressing:::
Place the mayonnaise, chili sauce, and pickle relish in a bowl and whisk to mix. Cover and refrigerate until using; it will keep for at least 3 days in the refrigerator.
:::pork loin:::
Butterfly the pork loin: Place the pork loin on a cutting board. Using a long, slender, sharp knife, cut the loin almost in half lengthwise through one side, but not all the way through. Leave both sides attached. Open up the loin as you would a book. Lay a sheet of plastic wrap on top and pound the meat with the side of a cleaver to flatten it slightly. Season the inside with salt and pepper and spread with mustard.
Arrange the pastrami over one side of the pork loin, followed by the sauerkraut and cheese slices. Sprinkle with chives. Fold the roast back together (like closing a book).
Position four 12-inch pieces of butcher’s string on your work surface so that the strings are parallel and roughly 2 inches apart. Lay a bacon strip across the strings so that it runs perpendicular to and in the center of them. Set the pork loin on top of the bacon so that the bacon runs down the length of the pork. Place a second bacon strip on top of the loin. Press the remaining 2 strips against the long sides of the loin. Bring the end strings and then the middle strings over the roast and tie it back into a tight cylinder with the bacon strips in place. Breathe a sigh of relief: The hard part is over. The pork loin can be stuffed to this stage several hours ahead, covered, and refrigerated.
Set up the grill for indirect grilling and heat to medium. Brush or scrape the grill grate clean and oil it well.
When ready to cook, place the pork roast on the hot grate, over the drip pan and away from the heat, and cover the grill. Cook the roast until cooked through, 1 to 1 1/2 hours. To test for doneness, insert an instant-read thermometer into the center of the meat; the internal temperature should be about 150°F. Transfer the cooked roast to a cutting board and let it rest for a few minutes, then remove and discard the strings. Cut the pork loin crosswise into 1/2-inch-thick slices and serve with the Russian Dressing.