Our rendition of au gratin potatoes relies on root vegetables grown in Alaska in August and September. Using a variety of root vegetables adds a lot of subtle flavors that are missing when just using potatoes.
Root vegetables grow remarkably well in Alaska, in fact, the largest turnip on record weighed in at just over 39 pounds at the Alaska State Fair in 2010 (that would make quite a lot of gratin!). Root vegetables can hold for months in an Alaskan root cellar, making them a perfect addition to any winter meal.
Depending on the starchiness of your root vegetables, they may not absorb as much of the milk as the recipe calls for.
1) Preheat the oven to 400 degrees. Butter a 2-quart gratin or baking dish.
2) Wash and peel all root vegetables.
3) Using the slicing attachment of a food processor, or by hand, thinly slice (about ¼”) all root vegetables. Keep submerged in water until all root vegetables are sliced.
4) Thinly slice onions.
5) Place the sliced root vegetables and onions in a large bowl, and season generously with salt and pepper. Add the thyme, and toss together.
6) Arrange the vegetables tightly in the gratin dish.
7) Add the milk, season with more salt and pepper if you wish, and place in the oven on the middle rack.
8) Bake 45 minutes; every 15 minutes, press the vegetables down into the milk with the back of your spoon.
9) After 45 minutes, pull gratin from oven and sprinkle with Gruyere or Parmesan cheese.
10) Return to the oven, and bake another 20 minutes, until the gratin is nicely browned and root vegetables are easily pierced with a knife.
11) Remove from the heat and let sit for 15 minutes, then cut and serve.
Advance preparation: You can make this several hours ahead of serving, and reheat, covered, in a 325 degree oven.
Filed In: Dinner