I started preparing this dish for guests about ten years ago, and now I cannot entertain in the fall or winter without a request for it. I’m happy to comply. Root Vegetable Gratin is now a selection on our ‘Thanksgiving Made Easy’ order form.
1 tablespoon butter, softened
1½ quarts (6 cups) béchamel *See recipe below
2 small smoked chili peppers (I use anchos or dried smoked jalapenos)
3 medium russet potatoes (about 3 pounds), peeled and thinly sliced into 1/8-inch-thick rounds
1½ cups fresh or canned roasted red peppers, cut into strips
Salt and freshly ground black pepper
4 cups shredded sharp cheddar cheese
1 medium sweet potato (8 ounces), peeled and thinly sliced into 1/8-inch-thick rounds
1 small or ½ large rutabaga (about 12 ounces), peeled and thinly sliced into 1/8-inch-thick rounds
Prepare Béchamel: Melt the butter in a heavy-bottomed saucepan. Stir in the flour and cook, stirring constantly, until the paste bubbles; don’t let it brown. After 2 or 3 minutes, whisk in the hot milk. Bring to a boil and cook, stirring or whisking constantly until the sauce thickens. Season with salt and pepper to taste. Lower the heat and cook, stirring, for 2 or 3 minutes more. Remove from the heat.
Prepare Gratin: Preheat the oven to 350F°F and grease a 12- to 14-inch round baking dish or a 9 x 13-inch rectangular baking dish with the butter.
Simmer the béchamel over low heat, add the whole dried chili, and steep for about 10 minutes. Remove the chili and discard.
Peel vegetables and slice them very thinly on a mandoline to 1/8-inch thickness. Place half of the russet potato slices in a single layer on the bottom of the dish. Top with a third of the red pepper strips. Season with salt and pepper. Evenly spread 1½ cups of the béchamel on top,covering the potatoes and red pepper strips. Sprinkle with 1 cup of the cheddar. Arrange the sweet potato slices over top,slightly overlapping in a spiral pattern. Season with salt and pepper and top with another ⅓ of the red pepper strips. Again top with 1½ cups bechamel followed by 1 cup of cheddar. Add the slices of rutabaga, slightly overlapping in a spiral pattern,and strew with the remaining red peppers strips. Again, add 1½ cups bechamel followed by 1 cup of cheddar. For the final layer,arrange the remaining slices of russet potato on top,slightly overlapping in a spiral pattern. Season with salt and pepper. Put the remaining 1½ cups béchamel and 1 cup cheddar on top.
Cover with aluminum foil and bake for 1 hour and 15 minutes. Remove the foil and bake until the top of the gratin is bubbly and nicely browned, about 20 minutes. A knife inserted in the center of the gratin won’t meet any resistance, but should pierce easily into the fully cooked and soft root vegetables.
Serving suggestion: This is great to eat piping hot right out of the oven, but it’s also good reheated the next day.
* To lighten this dish, you can make a cornstarch/water slurry, stir it into chicken broth,and thicken simmering until it achieves a béchamel-like consistency.
* Omit the chili pepper and/or roasted red pepper.
* Substitute turnips for the rutabaga.
Nutrition: Roasted red pepper strips add flavor, color between the layers, and lots of vitamin C.
Note: This recipe has been adapted from the Gigi Good Food Cookbook, Hudson Valley Mediterranean.