Potatoes Au Gratin Recipe

Potatoes Au Gratin Recipe: my Midwestern heart smiles at these tender, creamy layers with golden, cheesy edges. If you crave a cozy side that feeds a crowd without fuss, this one’s for you, and it takes about 1 hour 20 minutes start to finish.

Easy Potatoes Au Gratin Recipe

Potatoes Au Gratin Recipe shines because it layers ultra-thin potatoes with a garlic-thyme cream and a duo of cheeses for crispy edges and a luscious center. I slice the potatoes paper-thin so the sauce seeps into every layer. The oven does the rest and delivers a bubbling, bronzed top.

This method uses a quick stovetop cream base so the dish bakes evenly without curdling. I balance Gruyère’s nutty flavor with Parmesan’s salty punch, so the casserole tastes rich but not heavy. You get reliable results that suit both holiday spreads and weeknight comfort.

Ingredients You’ll Need

• Russet or Yukon Gold potatoes, 3 lb (Russets give extra starch and silkier sauce; Yukons hold their shape better)
• Heavy cream, 2 cups (swap half-and-half for a lighter version; avoid fat-free)
• Whole milk, 1 cup (or use all cream for extra richness)
• Gruyère cheese, 2 cups shredded (sharp cheddar works; Tillamook shreds melt well)
• Parmesan, 1/2 cup finely grated (adds salty depth; Pecorino works too)
• Unsalted butter, 3 tbsp
• Garlic, 3 cloves minced (jarred minced garlic saves time)
• Fresh thyme, 1 tsp chopped (or 1/2 tsp dried)
• Nutmeg, a small pinch (optional, but it rounds out the dairy)
• Kosher salt, 2 tsp, plus more to taste
• Black pepper, 1 tsp
• Flour, 1 tbsp for light thickening (or 2 tsp cornstarch for gluten-free; whisk into cold milk first)
• Onion powder, 1/2 tsp (pantry shortcut for sweet onion notes)
• Optional topper: extra 1/4 cup Parmesan for extra crunch

Equipment:

• 9×13-inch baking dish (ceramic or metal)
• Mandoline or sharp chef’s knife
• Medium saucepan and whisk
• Foil
• Cutting board and bowl
• Box grater

How to Make Potatoes Au Gratin

• Prep: 20 minutes
• Cook: 55–65 minutes
• Total: about 1 hour 20 minutes

1. Heat the oven to 375°F. Grease a 9×13-inch dish with 1 tbsp butter.
2. Slice the potatoes 1/8-inch thin. Keep slices in a bowl of cold water while you prep the sauce, then drain and pat very dry so the sauce clings.
3. Warm the sauce base: Melt 2 tbsp butter in a saucepan over medium heat. Add garlic and thyme; cook 1 minute until fragrant.
4. Whisk in flour (or cornstarch slurry). Cook 1 minute to remove raw taste. Pour in cream and milk, whisking until smooth.
5. Season the sauce: Add salt, pepper, nutmeg, and onion powder. Bring to a gentle simmer; whisk 2–3 minutes until slightly thick. Pull off heat and stir in 1 cup Gruyère and 1/4 cup Parmesan until smooth.
6. Layer the potatoes: Spread a thin spoonful of sauce in the dish. Shingle a tight layer of potatoes. Spoon over more sauce and a handful of Gruyère. Repeat layers until you use everything, finishing with sauce and the remaining cheeses.
7. Cover the dish with foil, tenting it so it doesn’t stick to the cheese. Place on a rimmed sheet pan to catch any bubbles.
8. Bake covered for 35–40 minutes until the potatoes start to soften. Remove foil and bake 20–25 minutes more until the top turns deep golden and the sauce bubbles around the edges.
9. Want extra color? Broil 1–2 minutes, watching closely.
10. Rest the gratin 10–15 minutes before serving. The layers set up and slice cleanly.

Cooking tips & Mistakes to Avoid

• Slice evenly. Thin, uniform slices cook at the same rate and give neat layers.
• Dry the potatoes well. Water dilutes the sauce and blunts flavor.
• Season each layer lightly. A pinch of salt and pepper on each row avoids bland bites.
• Don’t boil the sauce hard. A gentle simmer keeps it smooth and prevents splitting.
• Use fresh-grated cheese. Bagged shreds include anti-caking starch that can make the sauce gritty.
• Keep the foil tented. Direct contact pulls off cheese and ruins that bronzed top.
• Let it rest. Hot dairy needs a short breather to thicken into a scoopable dream.
• Avoid low-fat dairy. It separates and weeps instead of turning silky.

Variations I’ve Tried

• Gluten-free: Replace flour with 2 tsp cornstarch whisked into the cold milk; use certified GF cheeses.
• Vegan: Use unsweetened oat cream or cashew cream, vegan butter, and a meltable vegan mozzarella plus a little nutritional yeast.
• Add-ins: Fold in crispy bacon, caramelized onions, roasted garlic, or thin-sliced leeks. Sprinkle chopped chives or parsley on top after baking. Swap half the potatoes with thin-sliced sweet potatoes for a sweet-savory twist.

How to Serve Potatoes Au Gratin

Serve generous squares alongside roasted chicken, seared steak, glazed ham, or baked salmon. Add something crisp and green like lemony salad or garlicky green beans for balance. A bright white wine or a light, malty beer pairs well with the rich cheese.

Make-Ahead and Storage

• Make-ahead (best method): Bake fully, cool, cover, and refrigerate up to 2 days. Reheat covered at 350°F for 20–30 minutes, then uncover for 5–10 minutes to re-crisp.
• Assemble-ahead (day-of): Slice potatoes and toss them directly in the warm sauce to prevent browning, layer in the dish, cover, and chill up to 12 hours. Add 10–15 minutes to the covered bake time.
• Fridge: Store leftovers covered for up to 4 days.
• Freezer: Wrap tightly and freeze up to 2 months. Thaw in the fridge overnight, then reheat covered at 350°F until hot.
• Single servings: Reheat in a covered skillet over medium-low heat or in the microwave at 50% power, then finish under the broiler for a minute to revive the top.

Nutrition Information

Calories: about 540 per serving (8 servings). Protein: moderate from cheeses. Carbs: medium from potatoes. Fat: high from cream, butter, and cheese; swap half-and-half and reduce cheese to lighten.

Adaly Kandice

Potatoes Au Gratin Recipe

Potatoes Au Gratin is a classic comforting side dish featuring thinly sliced potatoes baked in a rich, cheesy cream sauce.

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Prep Time 20 minutes mins

Cook Time 1 hour hr

Total Time 1 hour hr 20 minutes mins

Servings: 6

Course: Dinner

Cuisine: American

Ingredients

  

• 2 pounds russet potatoes, peeled and thinly sliced
• 2 cups heavy cream
• 1 cup whole milk
• 2 tablespoons unsalted butter
• 2 cloves garlic, minced
• 1 1/2 cups shredded Gruyère cheese
• 1/2 cup grated Parmesan cheese
• 1 teaspoon salt
• 1/2 teaspoon black pepper
• 1/4 teaspoon ground nutmeg
• 2 tablespoons chopped fresh parsley

Instructions

 

1. Preheat oven to 375°F (190°C). Grease a 9x13-inch baking dish with butter.
2. In a small saucepan, melt butter over medium heat. Add minced garlic and cook until fragrant, about 1 minute.
3. Stir in heavy cream, milk, salt, black pepper, and nutmeg. Heat until just warm, do not boil.
4. Layer half of the sliced potatoes in the prepared baking dish. Pour half of the cream mixture over potatoes and sprinkle half of the cheeses.
5. Repeat with remaining potatoes, cream mixture, and cheeses.
6. Cover with foil and bake for 40 minutes. Remove foil and bake an additional 20 minutes until golden and bubbly.
7. Let cool for 10 minutes before serving. Garnish with fresh parsley if desired.

Notes

For best results, use a mandoline slicer for even potato slices. Gruyère can be substituted with Swiss cheese. Let the dish sit before serving for easier slicing.