To begin, prepare the Gaeng Liang paste. In a mortar and pestle, pound the shallots, garlic, chilies, shrimp paste, dried shrimp (if using), white pepper, and salt until a coarse, fragrant paste forms. Adjust chili according to your preferred heat level. For a more intense flavour, allow the paste to rest for 10-15 minutes before cooking.

Heat a medium sized pot over medium heat. Add the Gaeng Liang paste to the pot and stir-fry for about 2 minutes, until aromatic. This step releases the essential oils from the ingredients, creating the base of the soup’s flavour.

Add the vegetable broth or water to the pot, stirring well to dissolve the paste into the liquid. Bring the mixture to a boil. Ensure that the paste is fully incorporated into the broth, as this will distribute the flavour evenly throughout the soup.

Once the broth reaches a boil, reduce the heat to medium-low. Add the pumpkin and allow it to cook for 5-6 minutes, or until it begins to soften. The pumpkin provides a natural sweetness that balances the heat from the chilies.

Next, add the zucchini, baby corn, and mushrooms. Simmer for another 4-5 minutes, or until the vegetables are just tender but still retain some bite. Stir occasionally to ensure even cooking.

Season the soup with fish sauce (or soy sauce) and palm sugar, stirring until the sugar dissolves. Taste and adjust seasoning, adding more fish sauce or salt for saltiness or more sugar for sweetness as needed.

Just before serving, stir in the sweet basil leaves and let them wilt gently into the soup. The fresh basil adds a fragrant finish and enhances the flavour profile of the soup.

Serve the Gaeng Liang hot, directly from the pot, for a comforting and aromatic meal. This soup pairs beautifully with steamed jasmine rice, and you can garnish with extra fresh basil or sliced chilies for added flavour and heat.