First of all cut the potatoes into medium sized cubes,finely slice the onion,chop the ginger finely
Boil the above three ingredients in a pan
grind the coconut with the garam masala
when the potatoes are done add this coconut paste into it
boil it for 5 minutes and then remove it from flame
in another pan add 3 tsp coconut oil(optional),add mustard seed and a small onion finely chopped and curry leaves,when the mustard starts spluttering and the onion becomes red, remove it from flame and add it to the potato curry
a delcious potato stew is ready which can be served with chapathi,paratha and palappam