2. To make the marinade, whisk the brown sugar and vinegar together in a small bowl. Whisk in the ginger root, five-spice powder, sesame and peanut oils, salt and pepper. (This can be done in advance and stored in the refrigerator for 2 to 3 days.) Pour the marinade over the pork and marinate for at least 30 minutes or overnight in the refrigerator.
3. Meanwhile, thoroughly mix all of the ingredients for the chutney together in a small bowl. Season to taste with salt and pepper. (This can be done a day in advance and stored in the refrigerator.)
4. Preheat the grill to medium-high. Remove the pork from the marinade and season it with salt and pepper. (Discard any leftover marinade.)
5. Sear the pork on all sides. Lower the heat to medium and cook for 8 to 12 minutes, until the pork is just cooked through. Transfer the pork to a platter and let the meat rest for 2 to 3 minutes before slicing.
6. Serve 3 or 4 slices of pork on each plate, garnished with pinapple chutney and fresh cilantro sprigs.