You can google Hasselback recipes and get quite a few I'm sure but it's easy and something different. I use two wooden utensils(you could use chop sticks), place one on each side of the potato and carefully make thin slices. The sticks or utensils prevent you from cutting all the way through the potato.
I rub them down with olive oil and sprinkle with Kosher salt and put them on the grill to bake at around 375* You can do them in the oven too. Don't know how long because the size of the potatoes vary. I just check them after about an hour for tenderness. You can seasoned them with melted butter and garlic or whatever you like. Serve and Enjoy!
Fixin's like a baked potato works great too.