This is so easy it doesn't really justify a recipe but a recent conversation with somebody made me realise not everybody knows what a chip butty is.  The thing about chip sandwiches is that although technically any chip can work, not every chip does work.  French fries are too crispy, not enough fluff coupled with the fact that they don't hold enough heat to melt the butter and truly make it great.  Frozen chips are fine (as long as they are not skinny that is).  But, if you want a great chip butty the chips need to be freshly fried, either by yourself or a chippie. 

Ingredients
Either 2 crusty rolls or 4 slices of bloomer bread
20g butter
1 portion of chips
Salt
Vinegar (optional)

Method
Butter your rolls/bread generously (let's be honest with carb on carb your calorie intake should not be thought about here). 

Before placing your hot chips into your bun season with salt and vinegar (if using). Pile the chips generously into your roll or on your bread and with your hands firmly push down.

Cut in half and enjoy with ketchup or mayo - whatever is your poison.