Tip the flour into a medium bowl. Add the sour cream, egg, olive oil, and salt. Stir until a shaggy dough dorms. Then pour the dough onto a lightly-floured work surface, and knead until smooth. Wrap the dough in cling film and let rest for 20-30 minutes. Meanwhile, add 4 quarts of water to a large pot, and set it to boil.