1. Combine the marmalade, chipotle, zest, juice, rosemary, ¼ teaspoon salt and ¼ teaspoon black pepper in a mini prep and process until smooth. Scrape into a bowl. Glaze can be made 3 days in advance and stored covered in the refrigerator. Bring to room temperature before using.
2. Preheat the grill to 525 degrees for indirect grilling. Season the pork with salt and pepper and brush with oil.
3. Sear the pork over direct heat for approximately 1 minute per side until it achieves a rich, golden-brown color across all sides. Once seared, transfer the pork to the indirect cooking zone and lower the grill lid. Begin turning the protein every 2 minutes and when the internal temperature is within about 20 degrees of your final temperature, begin brushing with the glaze every 90 seconds or so and proceed until a digital thermometer reads an internal temperature of 145 degrees F for pork tenderloin.
4. Transfer the cooked pork to a cutting board, add a final layer of glaze, and tent loosely with aluminum foil to rest for 10 minutes. Finish by slicing the tenderloin into ½-inch pieces and drizzling with the accumulated board juices.
