Turnip and Potato Gratin Recipe

Name: Turnip and Potato Gratin Recipe
Prep time: 20 min
Cook time: 70 min
Total time: 90 min
Yield: 6 servings
Ingredients: 1 lb turnips, peeled and thinly sliced; 1 1/2 lb russet potatoes, peeled and thinly sliced; 1 1/2 cups heavy cream; 1/2 cup whole milk; 2 cloves garlic, minced; 1 1/2 cups gruyère cheese, grated; 1 1/2 tsp salt; 1/2 tsp black pepper; 1 tsp fresh thyme leaves

Thin layers of turnip and potato baked in garlicky cream until tender and golden-crusted on top. — Photo by Veronika Benz on Pexels

Turnips break up the starchiness of an all-potato gratin and add a faint mustardy edge, while the potato keeps the dish from tasting one-note vegetal, and a slow bake lets the cream thicken as it's absorbed instead of staying loose.

Prep: 20 min
Cook: 70 min
Total: 90 min
Servings: 6

Ingredients

Servings6

Using a different pan?

1 lb turnips, peeled and thinly sliced
1 1/2 lb russet potatoes, peeled and thinly sliced
1 1/2 cups heavy cream
1/2 cup whole milk
2 cloves garlic, minced
1 1/2 cups gruyère cheese, grated
1 1/2 tsp salt
1/2 tsp black pepper
1 tsp fresh thyme leaves

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Instructions

1Preheat the oven to 375°F (190°C) and butter a 9x13-inch baking dish.
2Warm the cream, milk, garlic, salt, pepper, and thyme in a saucepan over low heat until just steaming, then remove from heat.
3Slice the turnips and potatoes as thinly and evenly as possible, ideally with a mandoline.
4Layer the turnip and potato slices in the baking dish, overlapping and alternating the two, pouring a little of the warm cream mixture over every few layers.
5Pour any remaining cream mixture over the top and press the layers down gently.
6Cover tightly with foil and bake for 40 minutes.
7Uncover, sprinkle the gruyère evenly over the top, and bake uncovered for another 25-30 minutes, until the top is golden and a knife slides through easily.
8Let rest for 10 minutes before serving so the cream fully sets up.

Tips & variations

Swap gruyère for a sharp cheddar or a mix of parmesan and gruyère for a different finish on top.
A mandoline makes this dish dramatically faster and more even than slicing by hand, worth using if you have one.
Rutabaga can stand in for some or all of the turnip for a slightly sweeter, denser gratin.

Storage & reheating

Refrigerate leftovers, tightly covered, up to 4 days. Reheat individual portions in a 350°F oven for 15-20 minutes, covered loosely with foil, until warmed through.

Nutrition

A rich, cream-and-cheese-based side dish best served in modest portions alongside a lighter main.

Tips from the Tulo kitchen

Layer the vegetables snugly on their edges, standing rather than flat, it helps the gratin hold together in neater slices once baked.
If the top browns too fast before the center is tender, tent it loosely with foil and keep baking.

FAQ

Can I make this gratin ahead of time?

Yes, assemble it up to a day ahead, cover, and refrigerate unbaked. Bake straight from the fridge, adding roughly 10-15 extra minutes covered to account for the cold start.

Why is my gratin still firm in the center after baking?

Slices that are too thick are the most common cause. If a knife meets resistance in the center, cover and keep baking in 10-minute increments rather than pulling it out early.

Can I use only turnips or only potatoes instead of both?

Yes, but the balance is part of what makes this version distinct, potato alone leans starchy and turnip alone can taste sharp; the combination softens both.