This recipe is taken from Food for the soul.
Bring two cups of water to boil and add the chopped bottlegourd and ginger. Let it simmer for about 5 minutes with closed lid. (Do not overcook.)
Open the lid and add corn starch mixed with three teaspoons of water and coconut milk. Blend into a nice and creamy soup. Make sure no pieces of the bottlegourd is visible.
Bring the mixture to boil once again. Fold in white pepper powder, cilantro, and freshly squeezed lime.