We discovered this Savoyard dish on a week-long visit to Chamonix a few years back. I made it a few times at home, trying to find the right substitute for the Reblochon cheese ( which you cannot buy in the US because it is unpasteurized). Gruyère is acceptable, as is raclette, but not authentic in taste. But recently our guide from the Tour du Mont Blanc trek, knowing how much I like Tartiflette, sent me a whole Reblochon wheel (weighing 450g, so not huge). So before the weather turned too warm for this "winter food", I made the dish for dinner last night. It was every bit as wonderful as what we had in Chamonix.
With apologies to vegetarians and anyone who follows a Kosher or Halal diet, I will share the late Anthony Bourdain's recipe, which I modify a bit in execution but not in ingredients.