How do I fry potatoes for curry?
There are two easy ways to prepare dry potato fry/curry. First one which I always use is first boil the potatoes till tender (not mushy though), peel and cube them. It is important that they are firm and hold their shape . Then proceed with frying.  Add oil, temper spices, add the potatoes, do the seasoning, let the outside gets crusty(fryed) and there you have it . This method works fine and you won't find potatoes sticking to the bottom. The second method is direct cooking of potatoes in the pan(which you mentioned) and yes, they tend to stick to the bottom. I suggest you cut the potatoes into smaller pieces and use a non stick pan for frying. (To ensure it doesn't stick also to ensure it absorbs less oil). If you do not have non stick pan, then try frying with a little more oil than usual, give it some time, and then turn gently. It's ok if they stick little bit. They come off as u keep frying. Fry in low flame to begin with. And don't add spices like chilly powder or salt at the very beginning. They may stick to the bottom making the already existing problem multiply, and will get burnt. Once the potatoes are almost cooked and do no more stick to the pan, add the seasoning. I use both these methods for cooking potatoes and they work exceptionally well. Of course both have their own taste. Hope it's clear now. All the best!