Kamut flour can be sold as Kamut, Khorasan or even Egyptian Gold wheat. It is golden in colour, and I have only ever seen it sold as organic. If you cannot find Kamut, use wholemeal spelt in its place. Wholemeal spelt also has a nutty flavour that will work well in this pastry.
The secret to good pastry is to keep everything cold. I have hot hands, so tend to use a food processor to mix in the butter. You an easily do this step by hand if you prefer.
I have given an approximation for the amount of water you will require. The actual amount of water needed for the recipe is altered by so many factors, including the moisture content of your flour and humidity. Start with the lower amount and add more if necessary.
This pastry freezes well, and I often freeze leftovers. If frozen, allow to defrost in the fridge overnight if possible before use.
This recipe will make enough pastry to line a 22cm pie dish.