Preheat oven to 375˚F. Line a baking sheet with parchment paper or foil. Set aside. You can also use a large casserole dish.
Mix together the spices: brown sugar, paprika, garlic powder, salt, onion powder, dried thyme, dried rosemary and pepper.
Pat the pork loin dry with paper towels. Coat the pork loins all over with the spice rub.
Heat a large frying pan over medium-high heat. Once it's hot, add the olive oil and swirl the pan to coat. Add in the pork tenderloin. Brown the meat on all sides, about 3-5 mins each.
Place the pork on the baking sheet or in casserole dish. Add the butter on top (it's okay if it rolls off, but try to get it to stay) and roast for 30 mins, or until it reaches 145°F internally with meat thermometer. Halfway through roasting, remove the dish from the oven and loosely cover with foil. This will help prevent pork from drying out.
Remove the pork from the dish and add it to a cutting board. Let the pork sit for 10 minutes, then slice it into small pieces. Excess liquid can be drizzled over the pork before serving, or make it into a gravy (see notes section below).
Recipe Notes:
RUB – If your rub is not sticking to the loin, use a non-stick cooking spray and lightly coat the sides, then apply rub making sure to cover all sides and work in crevices with your hands.
DONENESS – All pork should have an internal temperature of 145°F before it is safe to consume. Unlike beef, pork needs to be cooked thoroughly and therefore there is no rare or medium rare option available.
The nutritional information provided is an estimate and is per serving. There are 8 servings in this recipe.