How to Make It
Coat cold cooking grate of grill with cooking spray, and place on grill. Preheat grill to low (about 275°F). Toss together the potatoes, salt, and 1/4 cup of the oil until potatoes are well coated. Place the potatoes on oiled grates; grill, without grill lid, until tender, 25 to 30 minutes, turning occasionally. Remove from grill.
Place the onion rings and whole peppers on grates, and grill, without grill lid, until slightly blistered and tender, about 15 minutes.
Cut the grilled potatoes into 1 inch pieces, and place in a large bowl. Chop the onions and peppers, and add to potatoes. Add the bacon, reserved drippings, mustard, cider vinegar, black pepper, and remaining 1/4 cup oil. Toss until combined, and serve immediately.