This is such a fun and easy recipe for fall! You don't HAVE to make the onions, but it's super simple to do and the tanginess of the onion partners perfectly with the sweet pork and gooey cheese. Plan to make this over and over again...
Peppercorn-Crusted Roasted Pork Loin (with Pickled Red Onion and Melted Gruyere)
For the Pickled Red Onions
1 cup water
1/2 cups apple cider vinegar
1 tablespoon granulated sugar
1 1/2 teaspoons kosher salt
1 red onion, thinly sliced
For the Peppercorn-Crusted Pork
1 tablespoon olive oil
1 boneless pork loin roast (about 2 pounds)
3-4 tablespoons Dijon mustard
3 tablespoons peppercorn mélange (tri-color peppercorns, sold next to the other peppercorns)
6 ounces sliced or grated Gruyere or Swiss cheese
To make the pickled red onions, whisk together the water, vinegar, sugar, and salt. Whisk until sugar and salt dissolve. Place the sliced onion in a jar and pour over the water mixture. Let sit at room temperature for 1 hour. Cover and chill until ready to use (onions will last up to 2 weeks in the refrigerator). Drain before using.
To make the pork, preheat the oven to 375 degrees.
Heat the oil in a large oven-proof skillet over medium-high heat (if you don’t have a large oven-proof skillet, you can transfer the pork to a roasting pan after it’s seared).
Add the pork to the hot pan and sear on all sides, until golden brown.
Brush the mustard all over the top and sides of the pork. Season the top and sides with the salt and black peppercorns (press the peppercorns into the meat to help them stick).
Transfer the pan to the oven and roast for 30 to 35 minutes, until a thermometer reads 140-145 degrees. Transfer the pork to a cutting board, cover with foil and let rest 10 minutes.
Slice the pork into 1-inch thick slices and serve with the cheese draped or sprinkled over top.