Using a knife and a dish cut the corn from the cob, the dish is for keeping the corn in one place because it usually jumps for freedom, he he. Blend the tomatoes, onion and 1 cup of water and put this in a cooking pot, heat until it boils. When boiling, add the corn and let it boil again. When it's boiling, add the salt and coriander, cover and let it cook for about 5 to 10 minutes, or until the corn is soft. You can serve it with a spoonful of cream (if you eat dairy). Enjoy! I personally love this soup and have it like every week!