Combine the lemon juice, water, and 1/2 cup (125 ml) of the fresh cilantro in an electric blender or food processor and blend at high speed until the mixture is reduced to a puree. Scrape down the sides of the container and add another 1/2 cup (125 ml) of the coriander and puree. Repeat until all the coriander is pureed. Add the remaining ingredients and puree until it is perfectly smooth. Taste and adjust the salt or sugar if necessary. Serve immediately. Will keep for about 1 week, tightly covered and refrigerated.