How to Make It
Stir together pork, grated red onion, red wine vinegar, salt, and pepper in large bowl until combined. Cover and refrigerate at least 4 hours or up to overnight.
Thread pork chunks onto metal skewers; discard marinade. Let pork stand at room temperature 30 minutes.
Preheat grill to high (450°F to 550°F). Place pork skewers on oiled grates; grill, covered, turning occasionally, until lightly charred on all sides, 12 to 15 minutes. (Alternatively, broil skewers on high with oven rack 5 inches from heat, turning occasionally, until lightly charred on all sides, 12 to 15 minutes.)
Remove pork from skewers, and transfer to a large bowl. With your hands, squeeze pomegranate arils over pork. Add onion slices, and toss to combine. Season with salt and pepper to taste. Serve with bell pepper jam and plum sauce.