For those using tamarind pulp, reserve 2 cups of the water and bring it to a boil with the tamarind pulp in a separate pot. Let it simmer until the pulp dissolves completely, then strain to extract the juice and set it aside. If using the Tamarind Mix, skip this step.

Place the quartered onions, halved green chillies, sliced tomatoes, and thinly sliced radish in a large pot. Add the remaining water (or the full 800 ml if not using tamarind pulp) to the pot and bring it to a rolling boil over medium heat.

Once the water reaches a boil, carefully add the shelled prawns, tender salmon belly, and the prepared tamarind mix (or the strained tamarind juice). Lower the heat slightly and allow the soup to simmer for 5 minutes, giving the flavors ample time to meld.

Add the fresh spinach leaves to the pot and let them cook for another 2 minutes, just until they are tender and wilted.

Finish the soup by seasoning with fish sauce and freshly ground black pepper according to your taste preferences. Stir gently to ensure the seasoning is evenly distributed.

Serve the soup hot in individual bowls, ensuring each portion includes a generous mix of prawns, salmon, and vegetables. Enjoy this tangy and comforting dish as a main course or a hearty starter.