I love Vietnamese Simple Fish Soup (Canh chua cá), and it’s one I remember my mother making for the family when I was a kid. It’s so simple and easy and cooks in only 20 minutes; no stock is required because you’re using a whole fish - the bones for the broth, and the fillets for the finished soup - a good way to extract flavor from just a few ingredients. The fish head has lots of rich flavor, so make sure you add it to the pot. Even on a hot summer day, this Vietnamese Soup is a great way to start a meal. Vietnamese Simple Fish Soup (Canh chua cá) should be made with flavorful tomatoes; don’t make it if your tomatoes taste like Styrofoam.
Following the directions in the sidebar , fillet the fish. Alternatively, ask your fishmonger to fillet the fish for you, but make sure you keep the skeleton, including the head.
Slice the fillets into 1-inch-wide strips and place them in a bowl. Add the fish sauce and cornstarch and toss to coat evenly. Chop the fish skeleton into thirds.
In a large pot, heat the oil over medium-high heat. Add the shallots and cook, stirring occasionally, for about 5 minutes, until just softened. Add the garlic and cook for an additional 30 seconds. Add the tomatoes, ginger, chile, the fish skeleton and head, and 2 quarts water, increase the heat to high, and bring to a boil. Lower the heat to a steady simmer and simmer for 1 hour. Remove the fish skeleton and head and discard.
Just before serving, add the fish strips and lime juice to the pot and simmer for 3 to 5 minutes, until the fish is opaque throughout. Taste the broth and adjust the seasoning with fish sauce.
Ladle into warmed soup bowls and garnish with the cilantro and toasted garlic, dividing them evenly. Serve immediately.
How to Fillet a Whole Fish
To fillet a whole fish, first trim off the tail, then make a cut behind the head, angling the knife toward the front of the fish. Cut down to the bone. Next make a long cut along the backbone of the fish and run the knife blade under the fillet, cutting as close to the bones as possible. Release the fillet from the skeleton. Flip the fish over and repeat on the second side.