• Preheat oven to 375°F.
• Trim any silver skin from the 2 pork tenderloins, then pat dry with paper towels.
• In a small bowl, mix together 2 Tbsp brown sugar, 1 tsp paprika, 1 tsp garlic powder, 1 tsp salt, ½ tsp onion powder, ½ tsp dried thyme, ½ tsp dried rosemary, and ½ tsp black pepper. Rub evenly over all sides of the pork.
• Heat 1 Tbsp olive oil in a large skillet over medium-high heat. Sear the tenderloins on all sides for 3–4 minutes per side, until golden brown.
• Transfer pork to a baking sheet or oven-safe skillet. Top with ¼ cup cold butter cubes.
• Roast uncovered for 12–15 minutes. Remove from the oven, loosely cover with foil, and return to the oven for another 8–10 minutes, or until the internal temperature reaches 145°F using a meat thermometer.
• Transfer pork to a cutting board and rest for 10 minutes before slicing.

To Make the Pan Gravy

• Place the skillet with drippings over medium heat. Whisk in 2 Tbsp flour and cook for 30 seconds.
• Slowly whisk in ¾ cup beef broth, scraping up browned bits from the pan. Simmer for 2–3 minutes until thickened.
• Whisk in 1 Tbsp Dijon mustard if using. Adjust thickness with additional broth if needed.