This cheesy potato gratin casserole is the epitome of comfort food, combining thinly sliced potatoes with a luscious cream sauce and a golden, cheesy crust.
Its velvety texture and rich flavor make it an irresistible crowd-pleaser!
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Recipe Information
- Prep Time: 20 minutes
- Cook Time: 1 hour
- Total Time: 1 hour 20 minutes
- Servings: 6
Ingredients
For this cheesy potato gratin casserole, you’ll need simple ingredients that pack maximum flavor:
- 4 large russet potatoes, peeled and thinly sliced (about ⅛-inch thick)
- 1 ½ cups heavy cream (substitute with cashew cream for a dairy-free version)
- 1 cup whole milk or unsweetened almond milk
- 2 garlic cloves, minced
- 1 teaspoon salt
- ½ teaspoon freshly ground black pepper
- 1 teaspoon smoked paprika (optional, for added depth)
- 1 ½ cups shredded Gruyère cheese (or sharp cheddar for a twist)
- ½ cup freshly grated Parmesan cheese
- 2 tablespoons unsalted butter, cut into small cubes
- 1 teaspoon fresh thyme leaves (optional, for garnish)
Equipment Needed
- 9×13-inch casserole dish
- Mandoline slicer or sharp knife
- Medium saucepan
- Whisk
- Aluminum foil
Instructions
1. Preheat the Oven
Set your oven to 375°F (190°C). Grease a 9×13-inch casserole dish generously with butter or cooking spray to ensure easy serving later.
2. Prepare the Cream Mixture
In a medium saucepan, combine the heavy cream, milk, minced garlic, salt, black pepper, and smoked paprika.
Heat the mixture over medium heat, whisking occasionally to prevent the milk from scalding.
Warm the mixture until it’s steaming but not boiling. This step helps infuse the cream with garlic and spice flavors.
3. Slice the Potatoes
Using a mandoline slicer or sharp knife, slice the potatoes into even, thin rounds. Uniform thickness ensures the potatoes cook evenly, creating that perfect melt-in-your-mouth texture.
4. Layer the Potatoes
Arrange half of the potato slices in overlapping layers at the bottom of your prepared casserole dish. Make sure the slices are tightly packed, as this helps create a cohesive dish.
5. Add the Cheese and Cream
Sprinkle half of the shredded Gruyère and Parmesan cheese evenly over the potato layer. Pour half of the warm cream mixture on top, ensuring it seeps into the layers.
6. Repeat the Layers
Layer the remaining potatoes in the same manner, followed by the rest of the cheese and cream mixture. Ensure every potato slice is coated with the creamy goodness.
7. Dot with Butter
Scatter small cubes of butter across the top layer. This step helps achieve a beautifully golden and crisp crust.
8. Bake the Casserole
Cover the casserole tightly with aluminum foil and bake in the preheated oven for 45 minutes. This allows the potatoes to steam and soften.
9. Finish and Crisp
After 45 minutes, remove the foil and bake for an additional 15 minutes. The top should turn golden brown, with bubbling cheese along the edges.
If you prefer a deeper golden crust, switch to the broil setting for 2–3 minutes, keeping a close eye to avoid burning.
10. Garnish and Serve
Sprinkle fresh thyme leaves over the gratin for a touch of earthy aroma. Allow the dish to cool for 5 minutes before slicing and serving.
This rest time helps the layers set, making it easier to plate neatly.
Serving Suggestions
This cheesy potato gratin casserole pairs wonderfully with a crisp green salad or roasted vegetables.
It also works as a decadent side dish for roasted meats or a vegetarian centerpiece when served with crusty bread.
Tips for Success
- Use Starchy Potatoes: Russet or Yukon Gold potatoes work best because they absorb the cream well and maintain their structure.
- Cheese Alternatives: Gruyère is classic for its nutty flavor, but feel free to mix in sharp cheddar, Fontina, or even Monterey Jack for variety.
- Make Ahead: Assemble the dish up to a day in advance, cover it tightly, and refrigerate. When ready to bake, let it come to room temperature first to ensure even cooking.
Variations
- Dairy-Free Option: Replace the cream with cashew cream and the cheese with a vegan alternative.
- Herby Twist: Add finely chopped rosemary or parsley to the cream mixture for a fresh flavor boost.
- Spicy Kick: Incorporate red pepper flakes or cayenne pepper for those who like a bit of heat.
Storage and Reheating
Store leftovers in an airtight container in the refrigerator for up to 3 days. Reheat in the oven at 350°F (175°C) until warmed through to retain its crispy top, or use the microwave for a quick option.
Why You’ll Love This Recipe
This potato gratin casserole is more than just a side dish. It’s a luxurious blend of textures — creamy potatoes with a cheesy, golden crust — that will elevate any meal. Its simplicity in preparation and versatility make it a recipe worth repeating!
