Combine the water, dried shrimp, bamboo shoots, tomato and sugar in a saucepan.
Bring to the boil over medium heat. Turn the heat down and simmer for 20 minutes.
Add winter melon and cook until soft and translucent. Turn off the heat and let cool.
Once cool, add the sesame oil and serve.
Bamboo shoots in brine, Chinese winter melon and dried small shrimp can be purchased in Asian speciality shops. If Chinese winter melon is unavailable substitute in bitter melon but salt for 30 minutes before using.