In a bowl combine the flour and salt and whisk well.
In a second bowl place the egg and whisk well. Then add the sour cream and water, again whisk well to combine.
Pour the liquid mixture into the flour. Using a Danish dough whisk, mix the ingredients until you have a moist dough.
This is a moist dough and will be sticky. You want it a bit sticky, and to feel a bit moist. Yet the dough needs to be able to be rolled out into thin sheets.
When all the ingredients are combined, pour the dough out onto a clean flat floured surface and knead until you have a good dough ball.
Cover with plastic wrap and place in the refrigerator for at least 1 hour, or overnight. You can freeze this dough as well.
The dough can be rolled out using a rolling pin or a pasta maker. I prefer using a pasta maker as it gives reproducible and quick results.