Clean carp, remove viscera and scales, prepare onion and ginger for frying, then add carp and oil, add water, not too much water, because wax gourd itself contains a lot of water. After boiling, add the wax gourd, preferably cut into pieces in advance, not too thin, and then simmer for about 40 minutes. At this time, soup is the most nutritious. Season with salt before cooking, and you can add a little chopped coriander.