Preheat the barbecue to maximum heat, 290°C (550°F).
Season the medallions with salt and pepper.
Close the lid and grill for 2 to 3 minutes on each side for rare doneness. (Wapiti is best when cooked rare. However, you may cook it longer if desired.)
Turn off the heat.
Place a slice of brie on each medallion and close the lid.
Cook for another minute.
Remove and let the meat rest for 2 to 3 minutes.
Garnish the meat with the pink peppercorns and apple.