In a pan add 2 tbsp of oil. Add the mustard seeds. Once it starts spluttering add the curry leaves.
Now add the finely chopped onions.
Add little salt and cook till the onions becomes translucent.
Now add the ginger garlic paste to this.
Cook in medium flame till the raw smell of the ginger garlic paste goes off.
Now add the chopped tomatoes. Cook for a minute.
Add sambar powder, turmeric powder and salt.
Mix well and cook for 3-4 minutes in medium flame.
Now add ½ cup of water.
Add butter beans and 1 cubed potato.
Mix well.
Cover this and cook for 20-25 minutes till the butterbeans gets cooked well.
Open in between and stir and sprinkle water if needed.
Once it is cooked and all the water evaporates, switch off the flame.
Butterbeans potato pirattal is ready.
Alternatively you can do it in the pressure cooker.
Cook everything in cooker and once you add butterbeans and potato cover and cook till one whistle.
If water is cook on high flame for 2 minutes so that the water gets evaporated.
Enjoy this with your meal.
This pairs well with rasam rice. Even it is a best side dish for chapati and poori.