Rutabaga Gratin
Rutabaga holds its shape better than potato when sliced thin and baked in cream, so the layers stay distinct instead of collapsing into mush, while its slight sweetness balances the sharp cheese and garlic. Simmering the cream mixture first with garlic before pouring it over the slices also means the gratin needs less time in the oven to fully soften.
- Prep
- 25 min
- Cook
- 1 hr 5 min
- Total
- 1 hr 30 min
- Servings
- 8
Ingredients
- 3 lbs rutabagas, peeled and sliced 1/8-inch thick
- 1 1/2 cups heavy cream
- 1/2 cup whole milk
- 4 cloves garlic cloves, minced
- 1 1/2 cups gruyere cheese, shredded
- 1/2 cup parmesan cheese, grated
- 2 tbsp unsalted butter
- 1 tsp fresh thyme leaves
- 1 tsp salt
- 1/2 tsp black pepper
- 1/4 tsp ground nutmeg
Nutrition per serving
- Calories
- 353
- Protein
- 11g
- Carbs
- 16g
- Fat
- 28g
Based on the recipe as written, one serving. Recalculates if you swap an ingredient above. An estimate only, exact values depend on the specific ingredients used.
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Instructions
- 1Preheat the oven to 375°F (190°C). Butter a 9x13-inch baking dish.
- 2Peel the rutabagas and slice them as thin as possible, about 1/8 inch thick, using a mandoline or a sharp knife.
- 3In a saucepan over medium heat, melt the butter and add the garlic. Cook for 30 seconds until fragrant, then stir in the cream, milk, thyme, salt, pepper, and nutmeg. Bring to a bare simmer, then remove from heat.
- 4Combine the gruyere and parmesan in a bowl.
- 5Arrange a third of the rutabaga slices in overlapping rows in the baking dish. Pour a third of the cream mixture over the top and scatter with a third of the cheese. Repeat with two more layers, ending with cheese on top.
- 6Cover the dish tightly with foil and bake for 35 minutes.
- 7Remove the foil and continue baking for 25-30 minutes, until the top is deeply golden and a knife slides through the rutabaga with no resistance.
- 8Let the gratin rest for 10-15 minutes before serving so the sauce thickens and sets slightly.
Tips & variations
- A mandoline gives far more even slices than a knife, which matters more here than in most gratins since uneven thickness means some pieces stay crunchy while others turn to mush.
- Swap half the rutabaga for potato or celery root if the flavor feels too strong on its own; the layers will still hold together the same way.
- A finely sliced onion layered in with the rutabaga adds sweetness as it caramelizes under the cream.
- Gruyere can be swapped for a sharp white cheddar or fontina if that's what's on hand.
Storage & reheating
Cover and refrigerate leftovers for up to 4 days. Reheat individual portions in a 350°F (175°C) oven for about 15 minutes, or in the microwave, though the top won't recrisp without the oven. The gratin can be assembled a day ahead, covered, and refrigerated unbaked; add about 10 minutes to the covered baking time if starting cold.
Tips from the Tulo kitchen
- Salting the rutabaga slices lightly and letting them sit for 10 minutes before layering draws out some moisture, which keeps the finished gratin from turning watery.
- Letting the dish rest before cutting is worth the wait; slicing into it straight from the oven causes the layers to slide apart on the plate.
FAQ
Why is my rutabaga gratin watery?
Rutabaga releases a fair amount of water as it bakes. Slicing it thin and evenly, and letting the finished gratin rest for 10-15 minutes before cutting, gives the starch time to thicken the liquid into a sauce instead of pooling on the plate.
Can I make this ahead of time?
Yes. Assemble the layers in the baking dish, cover tightly, and refrigerate for up to a day before baking. Bake covered for about 10 minutes longer than the recipe states since it will be starting cold, then uncover as directed.
Do I need to peel the rutabaga?
Yes. Rutabaga is often coated in a wax layer to extend shelf life, and the skin underneath is tough even after baking, so it should be peeled with a knife or sturdy vegetable peeler before slicing.
Can I use a mix of rutabaga and potato?
Yes, a 50/50 mix works well and mellows the rutabaga's flavor for anyone new to it. Slice both to the same thickness so they cook at the same rate.
