Wash and drain the prawns well. Marinate them with salt, turmeric and chili powder; place in the refrigerator until needed.
Grind all the ingredients listed under 'For the Masala Paste' to a fine paste1.
Heat coconut oil2 in a chatti / pot and add methi (fenugreek) seeds3.
Next, add the slit green chilies and curry leaves4.
Add onions and sauté until they soften and begin to turn translucent.
Add the ground masala paste.
Sauté the masala on low heat for 6 - 7 minutes or until it coagulates into a single mass.
Add 2 cups of warm water to the masala and stir well. Tip in the chopped raw mango.
Put a lid on and allow to simmer for 5 mins so that the mango softens. Taste check for salt and add a little more if needed at this point.
Add the prawns; stir gently and allow to simmer for a final 5 - 6 mins until the prawns curl and go opaque5.
Serve hot with steamed rice and enjoy!