Place the flour, eggs, spinach, salt, and nutmeg in the bowl of the processor and pulse 15 times for 6 seconds at a time. The dough should be elastic and a little sticky. Wrap it in plastic wrap and allow it to rest at room temperature for 50 minutes. (The wrapped dough can be stored in the fridge for up to 1 day.)
Note: If using frozen spinach, skip the blanching and simply thaw and press out excess water using a clean kitchen towel.
Cheese and mushroom sauce