Creamy, cheesy, and irresistibly indulgent, Leeks and Potatoes Au Gratin is the ultimate comfort food dish that’s perfect for family dinners or special occasions. This hearty recipe layers thinly sliced russet potatoes and caramelized leeks with a rich, velvety cheese sauce infused with garlic, thyme, and a hint of nutmeg. Topped with melted Gruyère, Parmesan, and golden, crunchy breadcrumbs, this casserole is baked to bubbly perfection. Easy to make yet deeply flavorful, this dish works beautifully as a show-stopping side for roasted meats or as a satisfying vegetarian main course. With a harmonious blend of textures and bold flavors, this gratin is a guaranteed crowd-pleaser.
Preheat your oven to 375°F (190°C). Grease a 9x13-inch baking dish with butter or olive oil.
Peel the potatoes and slice them thinly into 1/8-inch rounds. Wash the leeks thoroughly, trimming off the dark green tops and roots. Slice them into thin rounds.
In a large skillet, heat 1 tablespoon of olive oil over medium heat. Add the sliced leeks and cook until soft and slightly caramelized, about 5-7 minutes. Set aside.
In a medium saucepan, melt the butter over medium heat. Add the minced garlic and cook for 1 minute until fragrant.
Whisk in the flour to create a roux and cook for another 1-2 minutes, stirring constantly. Gradually add the milk and heavy cream, whisking to remove any lumps.
Stir in the thyme, nutmeg, salt, and black pepper. Bring the mixture to a gentle simmer and cook until slightly thickened, about 3-5 minutes.
Remove the saucepan from heat and stir in half of the Gruyère cheese and the Parmesan until completely melted.
Layer half of the sliced potatoes in the prepared baking dish. Top with half of the cooked leeks and pour half of the cheese sauce evenly over the layer. Repeat with the remaining potatoes, leeks, and cheese sauce.
Sprinkle the remaining Gruyère cheese evenly over the top. For added crunch, combine breadcrumbs with a tablespoon of olive oil and sprinkle the mixture over the cheese.
Cover the dish with aluminum foil and bake in the preheated oven for 30 minutes. Remove the foil and bake for an additional 20-25 minutes, or until the potatoes are tender and the top is golden and bubbling.
Allow the dish to rest for 5 minutes before serving. Enjoy piping hot as a side dish or main course!
Calories |
4578 | ||
|---|---|---|---|
% Daily Value* |
|||
| Total Fat | 259.5 g | 333% | |
| Saturated Fat | 144.4 g | 722% | |
| Polyunsaturated Fat | 7.8 g | ||
| Cholesterol | 765 mg | 255% | |
| Sodium | 6200 mg | 270% | |
| Total Carbohydrate | 393.1 g | 143% | |
| Dietary Fiber | 29.4 g | 105% | |
| Total Sugars | 54.3 g | ||
| Protein | 160.6 g | 321% | |
| Vitamin D | 7.2 mcg | 36% | |
| Calcium | 4138 mg | 318% | |
| Iron | 25.5 mg | 142% | |
| Potassium | 8353 mg | 178% | |
*The % Daily Value tells you how much a nutrient in a serving of food contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.