Potato Leek Gratin
Updated Nov. 17, 2025
- Total Time
- 1 hour 30 minutes
- Rating
- Comments
- Read comments
Advertisement
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.
Powered by
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.
Tastewise, this was very good. I followed the cooking time and it really needed another 30 minutes. I was using a dutch oven though so maybe a casserole dish would have worked better.
I made this for Thanksgiving and it was absolutely delicious. The leeks and thyme were perfect, and as others have stated I added a bit more garlic. Just the right amount of cream and I added a bit more Gruyère. This will be part of the regular rotation!
My family liked it! It took way more than 10 minutes to get the leeks close to browning. I called it when browned bits stuck to the bottom of the pan. I removed the bay leaf from the simmering sauce before pouring it over the leeks & potatoes.