Whatever Roots You Want Gratin
When we think of comfort food, we often think of potatoes—mashed, fried, or baked in cream. But this dish gives the rest of the root family their turn in the spotlight with a bubbling, cheesy gratin made from whatever’s on hand: sweet potatoes, beets, rutabagas, or turnips. A thyme- and garlic-steeped cream ties it all together, making a dish that’s gooey, colorful, and deeply comforting. Serves 4-6.
Ingredients
2 tablespoons butter, divided
3 medium onions, halved and sliced thin
1 ½ teaspoons salt, divided
3 cups root vegetables, such as beets, turnips, rutabaga, carrot, potato or parsnip
2 cups heavy cream
5 cloves garlic, chopped
½ teaspoon dried thyme
1 egg
1 cup Parmesan cheese, grated on a microplane
1 cup Fontina or another white melting cheese like gruyere or mozzarella
½ teaspoon ground black pepper
3 cups stale crusty bread cut into ½ inch cubes
Directions
Preheat your oven to 375°F and rub the inside of a 2-3 quart baking dish with 2 teaspoons butter.
Melt 1 tablespoon butter in an 8-10 inch saute pan or skillet and add the onions plus ½ teaspoon salt. Cover and cook for about 10 minutes over medium heat. Remove the lid, lower the temperature slightly, and continue cooking until the onions are nicely caramelized, about 15 minutes more.
Bring a 6-quart pot of heavily salted water up to a boil and set up an ice bath nearby. Add the root vegetables and cook for 2-3 minutes. Transfer the roots to the ice bath to stop the cooking. Once they are cool, drain and dry the roots.
In a large bowl, whisk together the egg, cream, thyme, garlic, cheeses, remaining salt, black pepper, and caramelized onions. Stir in the roots and bread. Transfer the gloppy mess to your baking dish and let it rest for at least 30 minutes or up to overnight before baking uncovered for 45 minutes. Serve warm.