Pat the pork loin dry with paper towels. Trim excess fat if desired, leaving a thin fat cap for flavor. In a medium bowl, whisk together olive oil, soy sauce, Dijon mustard, honey, minced garlic, chopped rosemary, thyme, smoked paprika, kosher salt and black pepper until emulsified. Place pork in a resealable plastic bag or shallow dish and pour marinade over, massaging to coat all sides. Seal and refrigerate for at least 1 hour, preferably 4 hours or up to overnight.

Bring to room temperature

Remove the pork from the refrigerator 30–45 minutes before roasting so it comes closer to room temperature; this promotes even cooking.

Roasting & Finishing

Preheat and sear

Preheat oven to 400°F (205°C). Heat a large ovenproof skillet over medium-high heat. Add 1 tablespoon vegetable oil. Remove pork from marinade (reserve marinade) and pat dry lightly. When oil is shimmering, sear pork on all sides until nicely browned, about 2–3 minutes per side, using tongs to rotate.

Roast

Transfer the skillet with the seared pork to the preheated oven. Roast until an instant-read thermometer inserted into the center reads 145°F (63°C), about 20–30 minutes depending on thickness. Begin checking at 18 minutes to avoid overcooking.

Rest

Remove pork from oven and transfer to a cutting board. Tent loosely with foil and let rest for 10–12 minutes. Resting allows juices to redistribute and carryover will raise temperature a few degrees.

Make pan sauce

While pork rests, return the skillet to medium heat on the stove (if your skillet is not stovetop-safe, transfer drippings to a saucepan). Add 2 tablespoons butter to the pan drippings and melt, scraping up browned bits. Pour in reserved marinade and 1 cup stock, and bring to a gentle simmer. Stir in apple cider vinegar and brown sugar. In a small bowl, whisk cornstarch with 1 tablespoon cold water to make a slurry and gradually whisk into the simmering sauce. Cook 1–2 minutes until slightly thickened. Taste and adjust seasoning with salt and pepper. If sauce is too sharp, add a little extra butter or a pinch more brown sugar.

Slice and serve

Slice the rested pork loin into 1/2-inch thick slices. Spoon warm pan sauce over the slices. Garnish with chopped parsley and serve with apple slices or roasted vegetables if desired.

Optional garnish & to serve

Arrange apple slices or roasted vegetables alongside the pork. Sprinkle chopped parsley over the meat and sauce just before serving for freshness and color.