Potato Leek Gratin
Updated Nov. 17, 2025
- Total Time
- 1 hour 30 minutes
- Rating
- Comments
- Read comments
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Ingredients
- 2tablespoons unsalted butter, more for greasing the pan
- 2large leeks, trimmed and halved lengthwise
- 1½pounds peeled Yukon Gold potatoes
- 1teaspoon kosher salt
- ½teaspoon ground black pepper
- 2thyme sprigs
- 1cup heavy cream
- 1fat garlic clove, finely chopped
- 1bay leaf
- ¼teaspoon freshly ground nutmeg
- ¾cup Gruyère, grated
Nutritional analysis per serving (6 servings)
350 calories; 24 grams fat; 15 grams saturated fat; 0 grams trans fat; 6 grams monounsaturated fat; 1 gram polyunsaturated fat; 27 grams carbohydrates; 3 grams dietary fiber; 4 grams sugars; 9 grams protein; 457 milligrams sodium
Note: The information shown is Edamam’s estimate based on available ingredients and preparation. It should not be considered a substitute for a professional nutritionist’s advice.
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Preparation
- Step 1
Heat oven to 350 degrees and butter a 2-quart gratin dish. Wash the leeks to remove any grit and slice thinly crosswise.
- Step 2
Using a mandoline or sharp knife, slice the potatoes into rounds, ⅛-inch thick. Toss with ¾ teaspoon salt and ¼ teaspoon pepper. Layer the rounds in the gratin dish.
- Step 3
Melt the 2 tablespoons butter in a large skillet over medium heat. Add leeks, remaining salt and pepper, and thyme. Cook, stirring, until leeks are tender and golden, 5 to 7 minutes. Discard thyme and scatter the leeks over the potatoes.
- Step 4
Add cream, garlic and bay leaf to the skillet, scraping up browned bits of leeks from the bottom of the pan. Simmer gently for 5 minutes. Stir in nutmeg.
- Step 5
Pour the cream over the leeks and potatoes and top with the Gruyère. Cover with aluminum foil and transfer to the oven. Bake for 40 minutes, uncover and bake until the cheese is bubbling and golden, 15 to 20 minutes longer. Let cool slightly before serving.
Private Notes
Comments
I've found the easiest way to clean leeks is to slice of roots end, split them down the middle, stand in a tall jug, run water over them til jug is full and water looks clear. Allow to stand in the water and any dirt usually sinks to the bottom of the jug.
I make this in layers -- half the potatoes, leeks, half the Gruyere, potatoes, pour cream, then the rest of the Gruyere. This is a very good dish!
One clove of garlic? As Lynne Rossetto Kasper would say, "Why bother"? I'd up it to 4-6 cloves. Richard Olney, in recipes such as Gratin Dauphinois, would also use a cut clove of garlic when he started the recipe to rub down the interior of the gratin dish, and then let it dry there as he continued on.
I followed the recipe as written. It was incredibly soggy. The flavors were basically good though. Right now my main question and thoughts are how do I save the leftovers and fix this and not throw them away? I’ve already used paper towels to sop up the excessive oil. Still I have to do something else maybe cook with more potatoes in another format? Very disappointing.
I roasted two leeks along with two bell peppers, for extra flavor, and layered them in with the potatoes, cream, and cheese.
I found I could make the whole dish a little bigger, to fill the size of a normal gratin dish. A little over 2 lbs potatoes, 3 big leeks, 2 cups cream, 3 garlic cloves and a little more cheese on top. I did a layer of 1/2 of the potatoes, then the leeks, poured 1/2 the cream on, then the other 1/2 of the potatoes, the rest of the cream mixture, then cheese. I also seasoned each layer with the kosher salt and some pepper :) Because it was bigger I cooked it for an hour before taking the foil off, then turned the heat to 400 to make the top cheese brown a little faster, which took a little over 20 minutes. Potatoes are forgiving and cooking for longer is never a bad idea in my book! Turned out fantastic, I will be making this again!