Cooking scalloped potatoes has always been more of a method as opposed to a recipe for me. I never look up a recipe to cook rice — I just make sure I know the ratio of liquid to rice, depending on the grain type, then make sure to use the correct method. I see scalloped potatoes the same way. Does the liquid cover the potatoes? Cool, cook it until it is done, cheese it and brown it. Sure, it is a little more nuanced than that, but not too much.
You can make almost any pan work for cooking scalloped potatoes if it is under 2½ inches deep. Thicker potatoes may take hours to cook, and if you layer the pan to only 2 inches, and the pan is another 2 inches or taller, the top of the potatoes will have a hard time browning after the initial low-temperature cook. A lid is nice, but not mandatory. If you are making in a casserole dish or other oven-safe cooking dish, use plastic wrap then foil. Most brands of plastic wrap don’t melt until at least 250 degrees. The layer of plastic wrap is next to the food with the foil on the outside. The plastic wrap is trapping steam and helping the food cook more evenly. Your potatoes will be done well before they reach 212 degrees.
You CAN use just about any type of potato, but I would recommend Yukon Gold or Russet. They have a much higher starch content than red potatoes and that will help with the final outcome. I prefer to have them peeled. Although this does remove some of the potatoes’ natural nutrients, it gives a much cleaner finish to the dish. You want to work quickly in order to utilize the natural starch and prevent the potatoes from oxidizing. Peel all of your potatoes and keep them in a large container or pot covered with water to prevent them from oxidizing. Make sure that you have your pan prepared with a small amount of fat and seasoning inside before starting to layer. Quickly (but without bodily injury) thinly slice the potatoes with a knife or a mandolin. This can range from an eighth of an inch to a quarter of an inch, thicker potatoes will just take a little longer to cook. Shingle the potatoes in a way that makes you happy, outside-in, inside-out, top to bottom then bottom to top — whatever arrangement makes the potatoes into a level stack every few rows. Season (salt, and if you wish pepper) each row, cheese every two rows. Repeat until you have achieved the desired thickness within about ½ inch from the top of the pan.
The potatoes need liquid to keep them from oxidizing as well as to cook. As long as the liquid just comes to the tops of the potatoes it should be fine. The starch from the potatoes may be enough to bind the whole dish together, but a little more would help. Thicken about a cup of milk with roux and add it to the potatoes once it has come to a simmer. Cover the remaining potatoes with cream. This is not an exact measurement, but once mixed with the thickened milk and starch from the potatoes, it will help bind and thicken the dish.
Not all cheese is created equal. Gruyére, Comté, mozzarella and asiago will all work well with scalloped potatoes, but don’t leave out the specialty cheese. Truffled pecorino and truffled Parrano or any other semi-aged truffle cheese that will melt might turn truffled scalloped potatoes into your new favorite side dish. The shredded cheese should go on liberally about every two layers, except for the top. Leave the top uncovered for the initial bake, make sure to reserve some cheese to finish at the end once the potatoes have cooked.
Once you have your potatoes layered, seasoned and covered (plastic wrap and foil or a lid) with finishing cheese reserved, it is now time for the initial bake. This is much lower than the finishing bake. You want to cook in the 300 to 325-degree range. I give you some wiggle room in case you happen to be cooking something else as well. This bake is just to cook the potatoes, depending on their thickness it can range from 45 minutes to an hour. Using a cake tester, wooden skewer, knife or any other piercing instrument start checking the potatoes after about 30 to 35 minutes. You check the potatoes by testing the resistance when piercing through the entire stack. You want to have very little resistance. Check more than one place, if you notice one side is becoming more tender than the other, rotate the pan. Once the potatoes are evenly cooked, remove the pan and turn the oven up to 400.
While your oven is heating to 400, remove the lid and evenly spread out your reserved layer of cheese. Once the oven is heated, place the uncovered pan into the oven for 10 to 15 minutes until the top is bubbling and is evenly golden brown. Remove the pan and allow to cool for another 10 to 15 minutes. The scalloped potatoes will not scoop well hot, not to mention they will also burn your mouth.
Salt and pepper as needed
1 tablespoon butter for pan
1 tablespoon butter for the roux
1 tablespoon flour for the roux
½ to ¾ pound shredded cheese (Gruyére or other cheese that will melt and flavor well)
Cream as needed
¼ to ½ cup cheese to finish top once cooked
Peel and reserve all potatoes in water. Melt 1 tablespoon of butter in a small saucepan and add in flour, whisking to make a roux. Stir in milk and season lightly, turn heat to low and bring to simmer until thickened, stirring every 30 seconds to a minute. Rub butter onto the inside of the pan and season lightly with salt and pepper. Slice and arrange potatoes, seasoning every layer, and cheesing every other layer. Pour thickened milk over potatoes, pour cream over potatoes until the potatoes are just thinly covered. Cover the potatoes and put into a 300 — degree oven for 45 minutes to an hour. After about 30 minutes, start checking the doneness with a cake tester or paring knife, rotate if needed to cook evenly. Once the potatoes are fully cooked (very little resistance from piercing remove from the oven, remove the lid, and turn oven to 400 degrees. Spread the last topping layer of cheese and place the pan back in uncovered once the oven is pre-heated. Bake for another 10 to 15 minutes until cheese is melted, bubbling and evenly golden brown. Allow the pan of potatoes to cool on a rack for 10 to 15 minutes before serving.
Brook Harlan is a graduate of the Culinary Institute of America in Hyde Park, New York. He is a culinary arts instructor at the Columbia Area Career Center.