Prepare the following, adding each to the same medium bowl as you complete it: Coarsely chop 2 garlic cloves; pick the leaves from 2 large fresh rosemary sprigs, then finely chop (about 1 tablespoon).

Add ¼ cup packed light brown sugar, ¼ cup soy sauce, ¼ cup olive oil, 2 tablespoons Dijon mustard, 1 tablespoon apple cider vinegar, 1 teaspoon kosher salt, 1 teaspoon black pepper, and 1 teaspoon Worcestershire sauce, and ½ teaspoon regular or smoked paprika. Whisk to combine.

Pour into a large zip-top bag. Pat 2 (1- to 1 ½-pound) pork tenderloins dry with paper towels. Add to the bag, seal, and massage to coat the pork tenderloins evenly with the marinade. Refrigerate, flipping the bag halfway through, for at least 4 hours or up to overnight.

Prepare an outdoor grill for zone cooking: For a gas grill, heat one half to medium-high heat (about 450°F to 500°F) and leave the other half unlit. For a charcoal grill, light a chimney of coals, pile the coals on one side of the grill, and leave the other side empty. Scrape the grill grates clean if needed.

Remove the pork tenderloins from the marinade and let any excess drip off. Place the pork tenderloins over direct heat. Cover and cook, turning the tenderloins every 2 minutes, until well-browned on all sides, about 8 minutes total. Move to indirect heat and continue to grill until the internal temperature registers 140°F to 145°F in the thickest part, 12 to 17 minutes more.

Transfer the pork tenderloins to a clean cutting board and tent loosely with aluminum foil. Let rest for 10 minutes before slicing crosswise. Garnish with chopped fresh parsley leaves if desired.

Twenty minutes before you plan to cook, place a 12-inch cast iron skillet or ovenproof skillet on the middle rack in the oven and heat the oven to 450°F.

Using oven mitts, carefully remove the hot skillet from the oven. Add 1 tablespoon vegetable oil and swirl to coat the bottom of the skillet. Remove the pork tenderloins from the marinade and pat dry with paper towels. Place them in the skillet.

Return the pan to the oven and roast for 10 minutes. Flip the pork and roast until the internal temperature registers 140°F to 145°F in the thickest part, 10 to 15 minutes more.

Transfer the pork tenderloins to a clean cutting board and tent loosely with aluminum foil. Let rest for 10 minutes before slicing crosswise. Garnish with chopped fresh parsley leaves if desired.