In a pan add oil and add the shrimp heads and tails. cook for a few minutes and get all the flavor out by squeezing the shrimp heads..
Take them out and in the same oil add onion. cook until golden brown.
make a slurry with salt, chili powder, turmeric powder, ginger garlic paste and mix well.
Pour that slurry into the pan once the onions brown.
mix well. add in some water to prevent burning.
Once oil seperates and gravy is cooked through, add in the shrimp and give it a mix.
After two to three minutes of cooking in high flame add in the taro stems.
mix everything together and cook for 8-10 minutes. stir often.
Taro stems naturally release water so you don't need to add any. unless you want a thin gravy. I like mine dry so after 6 minutes or so I'll turn the heat up and cook for another 5 minutes.
Add green chili and coriander and simmer in low heat for 5-7minutes.
It should be done by now, you'll see a nice slimy texture that means taro stems are cooked through properly.
serve with steam rice and a slice of lemon.
enjoy.