E-fu noodles are a variety of flat Chinese egg noodles made from wheat flour. They are known for their golden yellow color and chewy characteristics. The slightly chewy and slightly spongy texture of the noodles is due to the soda water used in making the dough (as opposed to regular non-carbonated water). The noodles are used most frequently in the Cantonese cuisine of Southern China and Hong Kong. They are also popular among overseas Chinatowns.