01 - Bring water to a boil in a large stockpot. Add pork chunks, skimming off any scum that rises to the surface for a clearer broth.
02 - Add quartered tomatoes and onions to the pot. Simmer for 20 minutes until pork begins to tenderize.
03 - Stir in sliced daikon radish and continue cooking for 10 minutes until slightly softened.
04 - Add eggplant slices, string beans, and green chili peppers. Simmer for 5 minutes until vegetables are partially cooked.
05 - Mix in the tamarind soup base, ensuring it dissolves completely. For fresh tamarind, boil pulp, mash, then strain into the soup.
06 - Season with fish sauce, salt, and black pepper. Taste and adjust seasoning as needed to achieve the desired balance of sour and savory.
07 - Add spinach or kangkong leaves and simmer for 2-3 minutes until just wilted. Avoid overcooking to maintain texture and color.
08 - Ladle hot soup into bowls and serve immediately with steamed white rice on the side.