Sweet Sour Water Spinach Soup with Fish

Overhead view of a bowl of Cambodian sweet sour fish soup with water spinach and fresh herbs. — Sweet and sour water spinach soup with fish, finished with fried garlic and fresh herbs.

5.0 from 1 vote

Sweet and sour water spinach soup with fish is a light, brothy Cambodian dish that balances tamarind, lemongrass, and fresh herbs. The fish cooks gently in the aromatic broth, while water spinach adds a soft green bite.

This is everyday home cooking, the kind of soup that appears alongside rice at a family meal. It comes together in one pot and relies on a few pantry staples, so you can make it on a weeknight without much fuss. If you enjoy sour Cambodian soups, this one is a good place to start.

What You Need

The ingredient list is short. Fresh lemongrass and garlic build the base, tamarind powder brings the sour note, and fish sauce and sugar round it out. Water spinach goes in at the end so it keeps a little texture. Use a firm white fish like catfish or basa; both hold up well in the broth.

Equipment

Soup pot: To heat the oil, sauté the aromatics, and simmer the broth and fish.
Chef’s knife: To chop the garlic, lemongrass, and herbs, and to cut the water spinach into 2–3 inch lengths.
Cutting board: To prepare the aromatics and vegetables safely.
Measuring spoons: To measure the oil, fish sauce, sugar, and tamarind powder.
Measuring cup: To measure the water.
Wooden spoon or cooking spoon: To stir the ingredients as they cook.
Small bowl: To hold the fried garlic while the soup simmers.
Ladle: To serve the soup and broth into bowls.

How to Make Sweet Sour Water Spinach Soup with Fish

Step 1: Fry the Garlic

Heat a large soup pot over medium heat. When the pot is hot, add the vegetable oil and chopped garlic. Sauté until the garlic turns golden brown but not burnt. Remove the toasted garlic with a spoon and set it aside in a small bowl for topping.

Step 2: Build the Lemongrass Broth

Add the minced lemongrass to the same pot with the hot oil. Stir well, then pour in the water. Bring the water to a bubbling boil.

Step 3: Cook the Fish

Add the fish chunks to the boiling water. Cook until the fish is tender and opaque. For a reliable doneness check, the fish should reach an internal temperature of 145°F (63°C); you can read more about safe cooking temperatures from the FDA’s safe food handling guidance.

Step 4: Add the Water Spinach

Add the cut water spinach to the pot. Stir gently and let it cook until just wilted. It cooks very quickly, so keep an eye on it.

Step 5: Season the Soup

Season with fish sauce, sugar, and tamarind powder. Stir well. Taste the broth and adjust the sourness, sweetness, or saltiness if needed. Tamarind powder can vary in strength, so add it a little at a time.

Step 6: Finish with Herbs and Toppings

Turn off the heat. Top the soup with the chopped mixed herbs, sliced chili pepper, and the reserved toasted garlic. Stir gently and serve hot.

Cooking Tips

Do not overcook the water spinach. It should stay bright green and slightly tender, not soft and dull.
If you are using tamarind powder instead of paste, add it gradually and taste as you go. The sourness can vary between brands.
The fried garlic softens quickly in the hot broth, so add it right before serving for the best texture.

How to Serve

Ladle the soup into bowls and serve it hot with steamed jasmine rice. It works as a main dish for a light meal, or as part of a larger Cambodian family spread. For another take on the same sour soup idea, you can try our Cambodian chicken sweet sour soup with water spinach. If you prefer beef, our beef water spinach sweet sour soup uses the same tamarind-and-herb approach. To understand how soups like this fit into Khmer meals, see our guide to Cambodian soup family meals.

Recipe Notes

Use Asian catfish or basa, and cut the fish into large chunks so it stays intact in the broth. If you are using frozen fish, thaw it completely and pat it dry before adding it to the pot.

Frequently Asked Questions

What does this soup taste like?

The broth is sour from tamarind, lightly sweet from sugar, and savory from fish sauce. Lemongrass and fresh herbs give it a clean, aromatic finish.

Can I use a different fish?

Yes, you can use other firm white fish. The supplied recipe uses Asian catfish or basa, but any firm fish that holds its shape in soup will work. Adjust the cooking time based on the thickness of the fish.

How should I store leftovers?

Let the soup cool, then store it in a sealed container in the refrigerator for up to 2 days. Reheat gently on the stove until hot. The water spinach may soften further, so it is best to add fresh greens when reheating if you have them.

Final Thoughts

This sweet and sour water spinach soup is a simple, everyday bowl that shows how Cambodian cooking balances sour, sweet, and savory flavors. The fish stays tender, the greens stay bright, and the fried garlic on top adds a warm, toasted note. Serve it with rice and let the broth do the rest.