Prepare the Broth

Start by preparing the broth, which will give your Tom Yum Soup its rich flavor. In a large pot, add 6 cups (1.5 L) of water and bring it to a simmer over medium heat.

Add the bruised lemongrass stalks, sliced galangal, torn kaffir lime leaves, crushed Thai bird’s eye chilies, and smashed garlic cloves to the water. These aromatic ingredients form the backbone of the soup's flavor.

Next, toss in the shrimp shells, fish sauce, and soy sauce. The shrimp shells will give the broth a deep, umami flavor.

Reduce the heat to low, cover the pot, and let the broth simmer gently for 90 minutes. This slow cooking process allows the flavors to meld and infuse the broth.

Strain the Broth

After 90 minutes, remove the pot from the heat. Carefully strain the broth through a fine mesh strainer into a clean bowl or pot, discarding the solids (lemongrass, lime leaves, chilies, and shrimp shells). You should be left with a beautifully fragrant, clear broth. Set this aside.

Sauté the Vegetables

In a separate pot, heat 1 teaspoon of vegetable oil over medium heat. Add the onion and tomatoes, sautéing them for about 2-3 minutes until they start to soften but still hold their shape. The large chunks of tomatoes and onions will add texture to your soup.

Combine Broth and Vegetables

Pour the strained broth over the sautéed onions and tomatoes. Stir in 1 tablespoon of soy sauce and 2 tablespoons of fish sauce for added depth of flavor. Bring the mixture to a gentle boil.

Add the Shrimp

Once the broth is boiling and the vegetables are tender, reduce the heat to low and add the peeled and deveined shrimp (300 g). Let the shrimp cook for 2-3 minutes. You’ll know they’re done when they turn pink and curl up.

Final Seasoning

Turn off the heat, then add 1 tablespoon of freshly squeezed lime juice. This adds a bright, tangy finish to the soup and balances the savory elements.

Serve

Ladle the soup into bowls, making sure to include some shrimp, tomatoes, and onion in each portion. You can garnish the soup with additional fresh herbs like cilantro or a few extra slices of Thai chili for added heat, if desired.