Whisk the garlic, vinegar, honey, and salt and pepper, to taste, in a bowl until smooth. While whisking, add the oil until the mixture has emulsified. Pour into a large serving bowl and stir in the olives and parsley.
Heat the grill to high. Brush both sides of the potatoes with canola oil and season with salt and pepper, to taste. Grill until lightly golden brown on both sides and cooked through. Coarsely chop the potatoes and add them to the dressing. Toss to coat and serve.