Peel the potato and boil it until soft. Remove from the water and allow to cool slightly. Place potato in a medium bowl and mash it thoroughly. Add half of the semolina flour and all of the salt; knead until the flour is absorbed. Add the remaining flour and knead until the dough forms a smooth ball. Cover the with plastic wrap and let it rest ten minutes.
Cut the dough into four pieces and roll each into a long tube measuring about 10-inches-by-1/2-inch . Cut into thumbnail-sized pieces. Dust the dough with extra flour and using a floured forefinger, make an indentation in each dumpling. Cook for about ten minutes, testing for appropriate doneness.