Cut the dough into four evenly sized pieces. Wrap the three pieces of dough you won’t use immediately in cling film so that they don’t dry out.
Different pasta machines can have different widest settings. To start, set the machine at its widest
Flatten one piece of pasta dough and flour it generously on both sides. Pass the flattened piece through the pasta machine.
Fold the rolled-out pasta dough into thirds, like a letter, and dust with flour. Turn the piece by 90 degrees so that the smooth edges are left-right, not top-bottom. Feed through the machine. Repeat this process until you get a smooth pasta sheet.
Repeated the folding and rolling steps a few times until the pasta sheet comes out smooth.
Generously dust the pasta sheet with flour and feed it through the next narrower setting on the pasta machine. (Note that there’s no more folding!) Keep reducing the settings until you get to a sheet about 1 mm thick.