I originally started making potato pastry when dh had to follow a very low fat diet for medical reasons. It fits in perfectly for rationing as I have to make the butter last so can use very little in recipes. I have adapted it a bit since then. It's very versatile and you can do whatever you want with it. The texture is a bit different to regular pastry, softer and chewier, I think this is because it has less fat. I really don't measure anything out unless I have to so change it as you go along if you want!
1 or 2 large baking potatoes
Grated cheese to taste
1-2 teaspoon butter
1) Peel and boil potatoes until tender. mash until smooth with butter and leave to cool.
2) Add about 1/4 cup milk per potato used and mix adding in flour, herbs and cheese until a dough is formed. It will take quite a lot of flour. You will know you have added enough flour as the dough will be firm.
3) 1 large potatoes worth is enough for me to make 8 mini pies.
4) Roll dough onto a well floured board. The dough will be fragile. Roll thinly otherwise it can taste quite dense.
5) If I'm making mini pies I make the bases of the pastry in the tin and par-cook before adding filling and pie top. I've found it works better that way.
6) If you want a richer pastry add more butter. I use a small amount because of rations. I have used sweet potato in the past and this has worked well too.
Sorry if my directions are not very good but I think it gives the idea! Now, must go, the Slow Tv Canal Boat program has just started-woop!!