Potato Leek Au Gratin

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This potato leek au gratin is a simple dish with leeks sauteed in butter, three kinds of cheese. Whole milk and heavy cream. POTATOES. It’s a fool-proof recipe for happy faces at the dinner table these holidays. This is one of my favorite fall recipes because it is just perfect with a roast or paired with lamb chops. For a more robust dish, use the the best gruyere cheese you can find.

The secret to a great Potato Leek Au Gratin is not trying too hard. Potatoes are plain delicious; there is really no need to smother them. And this is a point that this recipe clearly gets. These potatoes are gently scented with leeks and garlic and enriched with cream and Gruyere cheese. Prepared with cream and three kinds of cheeses, this rich gratin recipe makes a very decadent side dish for your Thanksgiving feast or your any of your favorite roasted meats.

Sliced leeks have a mild onion flavor that intensifies when sautéed and baked into layers of cubed potatoes with Gruyère, Blue Cheese and Parmesan cheese. This is a recipe that I would put on any menu, whether it was a holiday or any old day of the week, and be absolutely positive it would be well received by all.

Not what you are looking for? Try these other great potato recipes: Make-Ahead Mashed Potatoes, Sour Cream Mashed Potatoes or Garlic Goat Cheese Mashed Potatoes.


Potato Leek Au Gratin

Potato Leek Au Gratin scaled

Potato Leek Au Gratin

  • Author: The Modern Proper
  • Prep Time: :30
  • Cook Time: 1:15
  • Total Time: 1:45
  • Yield: 6-8
  • Category: Side Dish
  • Method: Baking


  • 4 tbsp Butter
  • 1 1/2 cups Whole milk
  • 1 cup Heavy cream
  • 3 Large garlic cloves finely chopped
  • 1 tbsp Stone ground mustard
  • 1/4 tsp Freshly grated nutmeg
  • 3/4 tbsp Kosher salt
  • 1 tsp Freshly ground pepper
  • 2 oz Blue cheese
  • 6 oz Grated gruyere cheese
  • 2 oz Freshly grated parmesan cheese
  • 3 lb Leek, white and light green portions, washed and sliced into 1/4 inch rings
  • 2 lb Russet potatoes (3-4 medium), peeled and cubed into 3/4 inch pieces
  • 3 tbsp Minced fresh chives


  • Position a rack in the center of the oven and heat the oven to 400°F. Grease a 9×13-inch baking dish or a large cast iron skillet with butter.
  • In 12 inch nonstick skillet over medium heat, melt the butter. Add the leeks, stirring until leeks are completely coated. Cover and cook, stirring occasionally, until the leeks are tender, about 20 minutes. Add the milk, cream, blue cheese, garlic, mustard, nutmeg, salt and pepper and simmer uncovered. Stir the mixture occasionally, until slightly thickened, about 15 minutes. Be careful not to let boil. Remove from heat, and allow to cool.
  • In a large bowl mix the gruyere and parmesan cheese.
  • Layer one third of the potatoes in the baking dish or skillet. Pour one third of the leek mixture over the top. Sprinkle one third of grated cheese and 1 tbs on chives. Repeat to make two more layers reserving the last laying of chives.
  • Cover Au Gratin with foil and bake for 45 minutes. Remove cover and continue baking until potatoes are completely tender when poked with fork and the crust is golden brown, about 30 more minutes. Allow to sit for 15 minutes after removing from oven. Garnish with reserved chives and serve.
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