Root Vegetable Gratin

Spiraled in a baking dish, root vegetables form the base of a delicious gratin that can be served as fittingly for Thanksgiving or any holiday as it can be for an indulgent weeknight dinner.  Potatoes give a familiar and comforting flavor while beets, turnips, rutabaga, and other varieties lend a bit more interest, with the choice of customization completely yours.  Red beets are particularly delicious, though they do cause the entire dish to become quite tinged with their color.  For this reason, you may wish to opt for the golden variety.

As a holiday dish, this one disappears quickly and can take the place of mashed potatoes if you are in the mood for a bit more texture.  The vegetables soak up much of the cream mixture as they bake and even more during the recommended cooling time, but there is still a bit of sauciness to each serving. Soft underneath, the fanned top of the root vegetable gratin stays firmer giving you the best of both worlds.

Ingredients

1 ¾ cups heavy cream
2 garlic cloves, minced
2 teaspoons fresh thyme leaves, chopped
Pinch grated nutmeg
Kosher salt and freshly cracked black pepper
1 ½ pounds russet potatoes
1 pound sweet potatoes
Additional 2 pounds of mixed root vegetables such as:
1 pound golden beets (see note on beets below)
1 pound rutabaga or turnips
⅓ cup grated parmesan cheese
4 ounces shredded Comté or Gruyère
1 tablespoon chopped fresh parsley

Note: If you select red beets, which happen to be delicious, the cream will become tinged with the pinkish red color unlike the golden color in the pictured gratin.

When selecting holiday side dishes, I love a combination of rich gratins and simply prepared vegetables. This recipe complements crispy brussels sprouts, charred green beans, and the more bright, acidic elements of the feast. If you typically serve a potato gratin, this recipe will remind you of the range of flavors offered by the season’s root vegetables.

How to Prepare the Cream Mixture

Combine the cream, minced garlic, thyme, nutmeg, and ¼ teaspoon each of kosher salt and pepper. Set aside while slicing the vegetables to give the flavors time to meld.  Since the cream mixture ultimately will bubble in the oven, milk or another substitute is not recommended.

How to Slice the Vegetables

Best when thinly sliced, the vegetable slices for this gratin can be cut easily using a mandoline set to about ⅛-inch thickness.  Thin vegetables soak up the cream mixture during the latter part of baking well and fan out to give the gratin a beautiful texture and look.

How to Prepare the Gratin

Preheat the oven to 375 degrees. Butter a large baking dish such as a 9 x 13-inch rectangular or similar oval shape. 

Combine the sliced vegetables in a large bowl with ¼ cup of cream mixture, 1 teaspoon kosher salt, and the full amount of grated Parmesan.  Toss the slices gently to ensure they are separated from each other and coated.  Fan out the slices then pour the remaining cream mixture on top of the potatoes and into the dish. Part of the vegetables should remain above the liquid line, and there should be some space at the top edge of the gratin dish as the cream mixture will bubble as it cooks. The amount of cream mixture can be adjusted as necessary for your dish size. Top with additional freshly cracked pepper.

Cover with foil and bake for 40 minutes.  Remove foil, sprinkle Comté and chopped parsley over top of vegetables, and bake for an additional 30 minutes uncovered, during which time the cheese will brown and the vegetables will become tender.

Let sit 15 minutes before serving.

Round out your holiday meal with homemade cranberry sauce, wild rice and cornbread stuffing, and festive desserts such as these cranberry curd tarts. If bread stuffing is on the menu, explore these tips for making the tastiest yet.