To remove moisture from the spinach, microwave it for a about 1 minute and then press as much water out of it as you can in a mesh strainer. Use towels (or paper towels) to further dry it. Once as dry as possible, chop it in a food processor until very fine.
With the flat beater on, combine the spinach and 4 cups flour into the stand mixer bowl and stir them up a bit. Then add the 4 eggs and 1 tbsp water and mix with the flat beater for about 30 seconds until it comes together.
4 cups all-purpose flour, 4 large eggs, 1 tbsp water
Switch to the dough hook and mix on low for about 2 minutes. Remove the dough and knead by hand for a few minutes, adding extra flour to the get the right consistency, which is stiff, but pliable and not sticky at all.
Let the dough rest for at least 30 minutes. Do not refrigerate or it will be too cold.
Cut the dough ball into eight equal pieces and work on one piece at a time. Use plenty of flour. Start with the widest setting on the roller and put it through a few times, folding it over in half in between passes. At the end your sheet should be the exact width of you pasta roller. If the dough starts to stick at all, dust the sheet of pasta with flour. Then you can work it through the roller until it gets down to your desired thickness (setting 4 is ideal for thick but manageable pasta).
Cut the pasta as desired and hang to dry on a pasta tree.