How to make the perfect garlic gratin potatoes and the common mistakes to avoid

It is difficult to conceive of a meal where dauphinoise potatoes would be an unwelcome addition

Creamy comforting potato gratin. 

Choose the right spuds

This is understandably the most important part of a gratin. Darina Allen favours floury potatoes for her ones. "The most important consideration is to find really good potatoes. I generally tend to favour the older varieties - eg, Golden Wonder or Kerr's Pinks, which are both floury and flavourful."