Put the flour and salt into a food processor, with the machine running add two-thirds of the beaten eggs. If the dough is too firm, add more egg, slowly and process again until a soft dough forms (the dough should be flexible, not sticky). Turn it onto a floured surface and need for about 12 minutes, or until smooth and elastic. Cover it with an inverted bowl for about 30 minutes.
Cut the dough in half. Starting with one of the halves, roll out – on a lightly floured work surface – as thinly as possible into a 14 inch square. Transfer to a large floured baking sheet and repeat all the steps with the second piece of dough. Leave to dry for 25 minutes.
When the dough surface looks dry, fold the dough loosely in half then in half again and repeat until you have a loosely folded strip of dough about 2 inches wide.. With a sharp knife, slice crosswise, straight down on one movement without dragging the knife into 1/8 to 1/2 inch wide.
Unroll the noodles, gently shaking to separate. Leave to rest for 1 minute. If not using immediately, hang the noodles over a wooden rack to dry.
Bring a large pot of salted water to a boil. Add all the noodles at once, cover and return to a boil. Cook for 2 minutes for the wider noodles slightly less for the thinner ones. As soon as the noodles rise to the surface they are cooked. Drain into a colander and serve in soup, toss with butter and cheese, or refresh under cold water to use in other recipes.