Cheesy Potato Gratin Casserole Recipe

A Creamy, Comforting, and Irresistible Side Dish for Every Occasion

When it comes to timeless side dishes that never go out of style, Cheesy Potato Gratin holds a permanent spot at the table. With its golden, bubbling cheese crust and layers of thinly sliced potatoes bathed in a rich, creamy sauce, this casserole is the definition of indulgence. Whether you’re planning a cozy holiday feast or need a weeknight dinner side that wows, this recipe delivers every time.

In this detailed guide, you’ll learn how to make a cheesy potato gratin casserole, with options for healthier and even vegan versions. From ingredient swaps to expert baking tips, we’ve packed this article with everything you need to master one of the most beloved au gratin potato recipes.

Why You’ll Love This Cheesy Potato Gratin Casserole

✅ Comfort food perfection
✅ Make-ahead friendly
✅ Customizable: vegetarian, healthy, or vegan
✅ Pairs well with nearly any main dish
✅ Elegant enough for holidays, easy enough for weeknights

What Is Potato Gratin?

Potato gratin, also called Gratin Dauphinois ou Potatoes au Gratin, is a French dish consisting of thinly sliced potatoes baked in cream and cheese until soft and golden. The top becomes beautifully crisp and bubbly, while the inside stays creamy and rich.

Ingredients for Classic Cheesy Potato Gratin

Cette classic potato gratin with Gruyere cheese uses simple, wholesome ingredients that come together in the most flavorful way.

Main Ingredients:

• 2 lbs Yukon Gold or Russet potatoes, peeled and thinly sliced (about ⅛-inch)
• 1 ½ cups heavy cream
• 1 tasse de lait entier
• 3 garlic clovesémincé
• 2 cuillères à soupe de beurre, for greasing the dish
• 1 cuillère à café de sel
• ½ teaspoon black pepper
• 1 teaspoon fresh thyme (or ½ tsp dried thyme)
• 1 ½ cups shredded Gruyère cheese
• ½ cup shredded Parmesan cheese
• Chives or parsley, for garnish (optional)

💡 Tip: Gruyère is the traditional choice, but you can also use Fontina, sharp cheddar, or Emmental cheese.

Optional Add-Ins & Variations

Want to personalize your au gratin potato recipes? Try adding:

• Sautéed leeks or caramelized onions
• Wilted spinach or kale
• Mushrooms
• Smoked paprika or nutmeg for warmth
• Sliced tomatoes layered between the potatoes
• Vegan or lighter substitutes (detailed below)

How to Make Cheesy Potato Gratin Casserole

Étape par Étape les Instructions

1. Prep Your Dish and Oven

Preheat the oven to 375°F (190°C). Grease a 9×13-inch baking dish or similar casserole with butter or olive oil. Set aside.

2. Slice the Potatoes

Using a mandoline slicer or sharp knife, slice the potatoes very thin—about ⅛ inch thick. Uniform slices help ensure even cooking.

🥔 Conseil Du Pro: Yukon Gold potatoes are creamy and hold their shape well. Russets are starchier and give a fluffier texture.

3. Make the Cream Mixture

In a saucepan over medium heat, combine the crème de lourdes, milk, l'ail, sel, poivreet thym. Heat until just steaming (don’t boil), stirring occasionally to let the flavors infuse.

4. Layer the Potatoes

Arrange half of the sliced potatoes in an overlapping pattern in the greased baking dish. Pour half of the warm cream mixture over them, then sprinkle with half of the Gruyère and Parmesan.

Repeat with the remaining potatoes, cream, and cheeses.

5. Bake the Gratin

Cover the dish with foil and bake for 40 minutes. Then, remove the foil and bake for another 25–30 minutes, or until the top is golden brown and the potatoes are tender when pierced with a knife.

If the top browns too quickly, cover loosely with foil again.

6. Let It Rest & Serve

Let the casserole rest for 10–15 minutes before serving. This allows the sauce to thicken and makes slicing easier.

Garnish with chopped chives or parsley for a pop of color and freshness.

Tips for the Best Potato Gratin

• Do not rinse sliced potatoes. The natural starch helps thicken the sauce.
• Use warm cream. Pouring cold liquid over the potatoes can affect the baking time.
• Rest before slicing. The resting time after baking is crucial for texture and flavor.

Healthy Cheesy Potato Casserole Tips

Pour un healthy cheesy potato casserole, try the following substitutions:

• Replace heavy cream with unsweetened oat milk ou low-fat milk + Greek yogurt
• Use reduced-fat cheese or less cheese
• Add cauliflower to reduce the potato content
• Bake with l'huile d'olive instead of butter

This lightened-up version keeps the indulgence but lowers the fat and calorie content.

Vegan Potato Gratin Recipe Variation

Craving a vegan potato gratin recipe? You can still enjoy this comforting classic! Try this plant-based version:

Ingrédients:

• 2 lbs potatoes, sliced
• 1 ½ cups unsweetened almond or oat milk
• ¾ cup raw cashews, soaked and blended
• 2 tbsp nutritional yeast
• 2 gousses d'ail
• 1 c. à soupe d'huile d'olive
• Salt, pepper, thyme
• ½ cup vegan cheese (optional)

Instructions:

1. Blend cashews with almond milk, garlic, salt, pepper, and nutritional yeast until smooth.
2. Layer potatoes in dish, pouring cashew cream between each layer.
3. Top with vegan cheese or more nutritional yeast.
4. Bake at 375°F for 60 minutes, covered for the first half.

This vegan version is creamy, nutty, and just as satisfying as the classic.

What to Serve with Cheesy Potato Gratin

Cheesy potato gratin is a versatile side dish and pairs beautifully with:

• Roast chicken or turkey
• Seared steak or grilled sausages
• Baked tofu or lentil loaf (vegetarian)
• Green salads or steamed broccoli
• Grilled mushrooms or asparagus

It’s also a standout dish on holiday tables, from Thanksgiving to Christmas.

How to Store and Reheat

Stockage:

Cool leftovers completely, then refrigerate in an airtight container for up to 4 days.

Réchauffage:

Cover with foil and reheat in a 350°F oven for 15–20 minutes, or until heated through. You can also microwave individual portions with a splash of cream or milk to revive the texture.

Foire Aux Questions

❓What’s the difference between scalloped potatoes and au gratin potatoes?

Scalloped potatoes typically use a cream or milk-based sauce, while au gratin potatoes include fromage—usually Gruyère or Parmesan—for a rich, golden crust.

❓Can I make this ahead of time?

Yes! Assemble the casserole up to 24 hours in advance. Cover and refrigerate, then bake when ready (add 10–15 extra minutes to the baking time).

❓Can I freeze cheesy potato gratin?

Yes, but with caution. Cream-based dishes can sometimes separate when frozen. To freeze, bake fully, cool completely, wrap tightly, and freeze for up to 2 months. Reheat from frozen in a 375°F oven, covered.

Nutritional Information (Per Serving – Classic Version)

• Calories: 360
• Fat: 24g
• Carbs: 28g
• Protein: 10g
• Fiber: 2g

For a healthier option, cut the cream and cheese portions in half or use dairy-free swaps.

Réflexions Finales

Cette easy cheesy potato gratin recipe proves that simple ingredients can create something spectacular. Whether you’re looking for a vegetarian potato casserole recipe for a weeknight dinner or a show-stopping side for a holiday feast, this dish is a go-to favorite. It’s creamy, comforting, and full of cheesy goodness that makes every bite better than the last.

And with flexible options like a healthy cheesy potato casserole or a plant-based vegan potato gratin recipe, there’s truly something here for everyone. Once you’ve tried it, you’ll find yourself coming back to this recipe again and again.