Marinade the washed and cleaned crabs with 1 tbsp of ginger garlic paste, 1/2 tsp turmeric powder, 1 tbsp red chilli powder and keep aside for 5-10 minutes while you prep the rest of the ingredients
In a wide and thick bottom pan, add 2 tbsp of oil and heat up. Add the marinated crabs and fry until the crab shells change colour and turn slightly orange
take it out from the pan and set aside.
In the same pan, add the remaining oil and add the chopped onions and curry leaves Fry until soft
Next add remaining 1 tbsp of ginger garlic paste and saute until the onions are nicely browned
Add all the remaining spice powders and saute for a minute
Next add the can of chopped or plum tomatoes along with salt and stir to ensure everything is mixed
Cover and cook for 5 minutes on a medium flame until you see the oil floating at the top
Now add the tamarind water or paste and let the mix come to a simmer
Gently tip in the previously fried crabs and add 1-2 cups of water to adjust gravy
Mix everything until all the masala coats the crabs and simmer covered for 10-15 minutes until the crabs are cooked and the oil floats on top. Tip in the slit green chillis into the gravy just before you turn off the flame.
Let the curry rest for at least 10-15 minutes before you serve to let the flavours develop.