In order to choose potatoes for different dishes, it is important to determine the amount of starch in them. It's easy to do: you need to cut the potato. If you have a thin whitish film on your knife, then there is a lot of starch in it. Potatoes with a high starch content have little moisture, so they are good for baking or frying. It absorbs liquid well (like butter or milk) and is great for purees. Low-starch potatoes better hold their shape after cooking and are ideal for soups and roasts. They are easily sliced when cooked and are therefore good for salads. And this is exactly the kind of potato we need for our recipe.