Preheat grill to medium-high heat.
Make a foil pouch for the potatoes and drizzle with olive oil and sprinkle with salt and pepper.
Cover the potatoes with the foil pouch and seal the top by folding foil over to create the pouch.
Grill the potatoes over a direct heat for 15 minutes on either side with the BBQ lid closed.
Once grilled, carefully open the packed and let potatoes rest and cool for 5 minutes.
Whisk together the mayonnaise, parsley, sugar, and mustard in a large bowl.
Adding the potatoes, tossing gently to coat.
Stir in the onion, blue cheese, and crumbled bacon pieces.
Serve as a side dish with your favourite protein.