I made this using half orange sweet potatoes and half blue swede potatoes which gave a spectacular colour combination. I also baked the potatoes whole in the oven before cooling and slicing them and used English rather than Dijon mustard. An instant hit!
I made this for a family BBQ. Everyone loved it. I made it ahead so it was not warm and I boiled the potatoes as the grill was quite busy. I also added crumbled bacon and garlic. It was a real hit.