first grind all the ingredients mentioned under masala curry paste to a smooth fine paste with some water.
if using grated coconut instead of coconut milk, then grind the coconut also with the rest of the masala curry paste ingredients.
keep the ground curry paste aside.
heat oil in a pot. fry onions till transparent.
add tomatoes and fry for 2-3 minutes.
now add the mushrooms. stir and saute the mushrooms.
first the mushroom will release water and the whole mixture will become slightly watery.
continue to saute till the water dries up and oil starts to leaves the sides of the mushroom mixture.
now add the ground masala paste and saute for 3-4 minutes, stirring often.
first add the thin coconut milk and simmer the curry for 5-6 minutes.
season with salt.
addition of thin coconut milk first will help in avoiding splitting of the thick coconut milk which we add later.
lastly add the thick coconut milk and let the mushroom caldin curry come to one boil. switch off the fire.
serve the mushroom caldin hot with some steamed rice or bread/rolls or goan bread.