Sinigang na Hipon

Bring the water to a rolling boil in a large pot. Add the quartered onion and tomatoes. Boil vigorously for 8–10 minutes, pressing the tomatoes against the side of the pot occasionally with the back of a spoon to help them break down and release their juices into the water. The tomatoes are not just aromatic — they provide body and sweetness that frames the sour tamarind. The broth will turn a faint pinkish-orange as they dissolve.

Add the tamarind paste (or sinigang mix) and stir until fully dissolved. Taste the broth — it should be bracingly, pleasantly sour. Add the daikon rounds and eggplant chunks. Adjust the heat to a gentle simmer and cook for 10–12 minutes until the daikon is just tender when pierced with a chopstick. The eggplant will absorb the sour broth and become silky. Sinigang's sourness should make you pucker slightly but not wince.

Add the head-on shrimp and the whole green chiles to the simmering broth. The shrimp go in raw and cook quickly — 3–5 minutes depending on size. The heads will leach their coral-orange fat directly into the broth, enriching it with umami. Do not overcook: shrimp tighten quickly and become rubbery beyond 5 minutes. Watch them change color and remove from heat the moment the last one turns fully pink.

Add the water spinach (or spinach) leaves and stems to the pot. They will wilt in 1–2 minutes — stalks first, leaves last. Season the broth with fish sauce and salt, adding them gradually and tasting after each addition. The final flavor profile should be bright and sour as the dominant note, with a salty umami backbone from the fish sauce and shrimp heads, and a background sweetness from the tomatoes. Serve immediately in deep bowls with steamed white rice on the side.