Plan to mix your dough the morning of your pasta dinner or the night before.
In the bowl of a stand mixer or food processor, combine all of the ingredients except the water. (The sourdough starter does not have to be at peak.) Use the paddle attachment for your stand mixer / the metal blade for your food processor.
Mix until all the ingredients are combined, about a minute, adding water 1 tablespoon at a time, until there are no powdery-dry areas.
Mash the dough together with your hands and transfer it to a clean countertop. Knead 2-3 minutes. The dough should be stiff. Add flour if it is sticky and water if it breaks apart with dryness.
Transfer the dough to a lightly oiled bowl or pyrex container. Press it into the container, cover, and note the level of the dough to watch the fermentation growth.
Leave the dough at room temperature for the day if you made it in the morning. If you prepped it in the evening, leave it out at room temperature as long as you can to get fermentation going, then refrigerate it while you sleep. Pull the dough out of the refrigerator in the morning. Aim for 40-90% growth, and if the dough starts to edge toward the high end of that range, refrigerate it until 30 minutes before you plan to use it.