The first step to making your Tuscan soup is to prepare the potatoes. Normally, this would not be the first step, however, when working with fingerling potatoes, preparation can be one of the most time-consuming parts of the recipe since there are simply so many potatoes. You will want to do a number of things to prepare the potatoes for going into your Tuscan soup a little later.
First off, hand wash all of the potatoes by hand under cool running water. Since potatoes come out of the ground and are usually (especially in the case of fingerling potatoes) stored on grocery store shelves in non-airtight packaging, it is a good precaution to wash the potatoes before you eat them to rince off any dirt or other contaminates. Just rub the potato in your fingers under cool running water (don't make the water so cool that it makes your hands too uncomfortable).
Second, get some kind of bowl or dish and fill it half-way with cold water. We will be putting the sliced potatoes into this water so they don't oxidize and turn brown as we do the next couple steps in the recipe.
Third, slice the fingerling potatoes into medallions 1/4 to 1/2 inch in thickness. Now, you might be thinking that we should peel the potatoes first, which I agree you would probably do with other kinds of potatoes, but there are a number of reasons not to peel fingerling potatoes:
Since the potatoes are so small, peeling them can be dangerous. You might end up peeling your fingers too.
The skin on fingerling potatoes is much thinner and softer than the skin on other kinds of potatoes. So, especially after we boil them for a while, the skin will be plenty tender to eat.
Potato skins, like the skins of many fruits and vegetables, actually contain a lot of nutrients.
It takes a really long time to peel one and a half pounds of fingerling potatoes.
Place the potato slices into the container of water to prevent them from browning.
Once you are done slicing all of the potatoes, move on to the next step.