ROOT Vegetable Gratin
- 30m Prep Time
- 1h 15mCook Time
- 1h Ready In
A colorful gratin made with layers of root vegetables like russet potatoes, sweet potatoes, turnips, parsnips, and yellow beets, baked in a creamy Parmesan and herb sauce. It's a hearty side dish that stays hot and reheats well.
Ingredients
- 14.8 ml unsalted butter
- 680 g russet potatoes ends trimmed, peeled, sliced into ¼-inch-thick discs
- 454 g sweet potatoes ends trimmed, peeled, sliced into ¼-inch-thick discs
- 227 g turnips ends trimmed, peeled, sliced into ¼-inch-thick discs
- 227 g parsnips ends trimmed, peeled, sliced into ¼-inch-thick discs
- 227 g yellow beets ends trimmed, peeled, sliced into ¼-inch-thick discs
- 237 ml heavy cream
- 1 grated Parmesan cheese
- 14.8 ml fresh rosemary finely chopped
- 9.86 ml fresh thyme finely chopped
- 9.86 ml kosher salt
- 2.46 ml freshly ground black pepper
- 10 small sage leaves
- 3 medium onions
- unsalted butter hearty pat
- garlic powder
- kosher salt
- Lawry's Seasoned Salt
Nutrition (per serving, estimated)
Estimated based off 14 of 18 identified ingredients (per 100 g food data, scaled by amount).
Vitamins & minerals
- Calcium: 196 mg
- Iron: 2.24 mg
- Magnesium: 61.8 mg
- Phosphorus: 212 mg
- Potassium: 864 mg
- Zinc: 1.41 mg
Let's Prepare
Collect
Gather these ingredients — no prep needed yet.
- 14.8 ml unsalted butter
- 237 ml heavy cream
- 1 grated Parmesan cheese
- 9.86 ml kosher salt
- 2.46 ml freshly ground black pepper
- 10 small sage leaves
- 3 medium onions
- garlic powder
- kosher salt
- Lawry's Seasoned Salt
Prepare
- 680 g russet potatoes, ends trimmed, peeled, sliced into ¼-inch-thick discs
- 454 g sweet potatoes, ends trimmed, peeled, sliced into ¼-inch-thick discs
- 227 g turnips, ends trimmed, peeled, sliced into ¼-inch-thick discs
- 227 g parsnips, ends trimmed, peeled, sliced into ¼-inch-thick discs
- 227 g yellow beets, ends trimmed, peeled, sliced into ¼-inch-thick discs
- 14.8 ml fresh rosemary, finely chopped
- 9.86 ml fresh thyme, finely chopped
- unsalted butter, hearty pat
Let's Cook
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Step 1.
Preheat the oven to 375°F. Grease an 8-by-11-inch oval gratin dish (or similar) with 1 tablespoon unsalted butter and set aside.
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Step 2.
In a large mixing bowl, toss together the sliced russet potatoes, sweet potatoes, turnips, parsnips, yellow beets, 1 cup heavy cream, ⅔ cup grated Parmesan cheese, 1 tablespoon chopped fresh rosemary, 2 teaspoons chopped fresh thyme, 2 teaspoons kosher salt, and ½ teaspoon black pepper until well combined.
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Step 3.
Transfer the vegetable mixture to the prepared dish. For a nice presentation, stack the slices vertically in rows or a spiral, stuffing small pieces into gaps as needed. The pan will seem full, but the vegetables will soften and cook down. Pour any excess cream and herbs over the top, then arrange 10 small sage leaves on top. (At this point, you can cover and refrigerate for up to 1 day; if doing so, add 10 minutes to the first baking period.)
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Step 4.
Cover the dish tightly with aluminum foil, place on a baking sheet, and bake for 30 minutes. Remove the foil and bake uncovered for 15 minutes.
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Step 5.
Sprinkle the remaining ⅓ cup Parmesan cheese over the gratin and bake uncovered for another 30 minutes, until the tops are beginning to brown and a toothpick inserted into a stack meets no resistance.
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Step 6.
Let the gratin cool for 10 minutes before serving.