Combine spinach and a few drops of water in a saucepan. Heat, stirring occasionally, over medium heat until wilted. Drain excess liquid. Transfer spinach to blender and blend until finely pureed.
In processor combine flour, egg, salt and spinach; blend until well combined. Blend in water, a few tablespoons at a time, until a mealy dough is formed.
Turn dough out and shape into 4" balls. Press dough into 1" thick disks; wrap tightly in plastic wrap. Let dough sit 30 minutes before rolling and cutting.
Roll the dough out or flatten with your hand. Set pasta machine to it widest setting and feed dough through machine. Reroll the dough, narrowing the setting on the pasta machine each time, until the sheet is very thin. Cut into desired shapes. Cover loosely and refrigerate until needed.