From America's Test Kitchen Season 13: Meat and Potatoes à la Francaise
In the old days, this casserole of potatoes and onions was baked beneath a roast, which allowed the casserole to be seasoned by the savory fat and juices of the roast. To get the same luxurious results without the roast, we started by rendering a small amount of bacon, which lent the dish a meaty flavor with a hint of smokiness. We then browned the onions in the rendered bacon fat, which gave the dish remarkable complexity.
In the old days, this rich dish got its deep flavor and silky texture from meat drippings. Could we get the same luxurious results without a roast?Watch the Video
Serves 6 to 8 as a side dish
Do not rinse or soak the potatoes, as this will wash away their starch, which is essential to the dish. A mandoline makes slicing the potatoes much easier. For the proper texture, make sure to let the casserole stand 20 minutes before serving.