heat oil and pop in cumin seeds, crushed ginger garlic, chopped green chilli, curry leaves and fry for a minute until raw smell leaves.
add sliced and diced onions and fry till brown.
finely chop tomatoes and add it with salt. fry till mushy.
add turmeric powder, chilli powder, coriander powder, garam masala and mix well.
further add chopped potatoes, salt and mix well.
add 1.5 cups water and mix well. you can also pressure cook until potatoes are mushy. Close and cook until potatoes are soft and mushy.
mash well until potatoes are broken.
furthermore, add coconut milk, chopped coriander leaves, close and cook for 10 minutes. open and mix once.