Remove the thick cream from the top of the coconut milk and top the can with water to create thin milk.
Blend chillies, turmeric, coriander, pepper, cumin, and 60ml of thin coconut milk into a paste.
Grind poppy seeds finely and stir them into the remaining thin coconut milk along with the spice paste.
Fry onions, garlic, and ginger in oil until the edges turn brown.
Add the coconut milk mixture, tamarind, salt, and 120ml of water.
Cover and simmer the sauce gently for 10 minutes.
Add prawns and reserved thick coconut cream, simmering until the prawns are opaque.