Description
Au gratin potatoes are a creamy, cheesy side dish made from thinly sliced potatoes baked in a rich sauce until tender with a golden, bubbly crust. This indulgent recipe pairs perfectly with holiday meals, family dinners, or special occasions. The dish features tender potatoes, caramelized onions, garlic, herbs, and a luxurious blend of Gruyere and Parmesan cheese for a rich and satisfying flavor.
Ingredients
- Russet potatoes – 2½ lbs, thinly sliced (1/8-inch)
- Yellow onion – 1 small, finely diced
- Garlic – 4 cloves, minced
- Fresh thyme leaves – 2 teaspoons
- Heavy cream – 2 cups
- Milk – ½ cup
- Gruyere cheese, shredded – 2 cups
- Parmesan cheese, grated – ½ cup
- Butter – (for sautéing onions)
- Salt – ¼ teaspoon (plus extra for potato layers)
- Black pepper – ¼ teaspoon
- Fresh chives – for garnish
Instructions
- Preheat oven to 350°F (175°C). Grease a 2.5-quart baking dish or 9×13-inch casserole dish.
- Combine heavy cream and milk; microwave 1 minute to warm.
- Melt butter in a pot over medium heat. Add onions and soften for 10 minutes, stirring.
- Reduce heat to medium-low; cook another 10–15 minutes until caramelized.
- Stir in garlic and thyme; cook 2 minutes.
- Gradually stir in warmed cream/milk mixture.
- Bring to a simmer, then remove from heat. Slowly stir in Gruyere and Parmesan until melted. Season with salt and pepper.
- Slice potatoes into 1/8-inch thin slices using a mandoline.
- Layer 1/3 of potatoes in the baking dish; lightly sprinkle with salt. Add 1/3 of cheese sauce. Repeat for 3 total layers.
- Cover and bake 1 hour.
- Uncover and bake 30 more minutes until bubbly and golden.
- Optional: Broil at 425°F (220°C) for 1–2 minutes for deeper color.
- Rest 5–10 minutes. Garnish with chives and serve.
Notes
- For best results, use freshly shredded cheese , not pre-shredded for better melting.
- Letting the dish rest helps the sauce thicken.
- Yukon Gold potatoes can be used but will produce a slightly thinner sauce.
- To customize: add smoked paprika, nutmeg, bacon, mushrooms, or herbs.
- Vegan variation: use olive oil, plant-based cheese, and coconut milk.
- Prep Time: 25 minutes (onion cooking + slicing)
- Cook Time: 1 hour 30 minutes
- Category: Side Dish
- Method: Baked
- Cuisine: French / American
Nutrition
- Serving Size: 1 portion (⅛ of recipe)
- Calories: 420
- Sugar: 3 g
- Sodium: 430 mg
- Fat: 29 g
- Saturated Fat: 17 g
- Unsaturated Fat: 10 g
- Trans Fat: 0 g
- Carbohydrates: 30 g
- Fiber: 3 g
- Protein: 13 g
- Cholesterol: 105 mg