Try this French Potato Soup (Potage Parmentier) recipe.
Potage Parmentier relies entirely on the starchy nature of waxy-to-medium potatoes like Kennebecs to achieve its traditional emulsion without requiring added flour or cornstarch. When scaling this classic French soup up or down, operators must recognize that liquid evaporation rates do not scale linearly in broad pots, meaning the initial cooking water volume requires careful monitoring during the two-hour simmer to prevent scorching. Selecting heavy-bottomed cookware ensures that the extended heat exposure breaks down the cell walls of the leeks and onions evenly into a tender purée.
Passing the cooked roots through a mechanical food mill rather than a high-speed blender yields a superior texture by shearing fibers cleanly instead of releasing excess free starch that can turn the soup gluey. Once the purée returns to the reserved cooking liquid, incorporating butter and heavy cream introduces milk solids that demand gentle reheating just below a simmer; boiling the mixture post-dairy risks breaking the emulsion and separating the fats. Adjusting the salt should always occur strictly after the dairy additions, as cream mutes sodium perception on the palate.
Storing leftover portions requires refrigeration within two hours in an airtight glass container, where the soup will keep safely for up to three days. Reheating chilled portions demands low heat on the stovetop accompanied by a gradual splash of water or milk to restore the original pouring consistency, since the starches continue to bind remaining moisture as the soup rests overnight.