2cshredded gruyere cheese, divided (1 C filling, 1 C topping)
1/2cBlackeyed pea relish (Striplings), plus more for garnish
Preheat oven to 450°F.
In a large oven-safe skillet over medium-high heat, melt butter.
Add onions and 1/2 cup beef broth and cook until the onions are browned and tender (approximately 15-20 min). Transfer cooked onions to a bowl and tent to keep warm.
Butterfly the pork. With the pork on a cutting board, hold a knife blade parallel to the board and carefully make a lengthwise cut about 1/3 of the way from the bottom, stopping about 1 inch from the opposite end, being careful not to cut through.
Open the loin like a book.
Cover the entire cut of meat with plastic wrap and pound to an even 1/3 inch thickness.
In a small bowl, combine oil, salt, pepper, and Italian seasoning. Rub over both sides of pork loin.
Top the pork loin with half of the cooked onions and half of the shredded cheese. Spread blackeyed pea relish over loin.
Tightly roll the pork loin to completely enclose all of the fillings. Using cooking twine, tightly secure the roll.
In the same skillet over medium heat, add the pork loin to the pan and sear on all sides (about 5 minutes on each side).
Pour remaining ½ cup beef broth over the loin.
Transfer the skillet to the oven and cook for 25-30 minutes or until the pork loin reaches an internal temperature of 145 °F. Occasionally baste the pork loin with the pan juices.
Increase oven temperature to broil. Top pork loin with remaining cheese and onions and cook for 5 minutes or until cheese is melted and golden brown.