Do not overcook the vegetables or shrimp, as they will lose their vibrant color and become limp. The soup should be served immediately after cooking to maintain the crisp texture of the snow peas.
If you cannot find nam plah (fish sauce), you can substitute with regular Asian fish sauce, though the flavor profile will be slightly less complex.
For best results, bruise the lemongrass stalks with the back of a knife before adding them to release their oils.
This soup is best enjoyed fresh. If storing leftovers, keep the broth and solids separate if possible to maintain texture, and reheat gently.