Gruyere Potatoes Au Gratin

4.94 from 15 votes

Try these foolproof Gruyere Potatoes Au Gratin! They’re thin sliced potatoes baked in rich cheesy sauce until perfection.This is a classic side dish recipe and will be a prefect compliment for a simple family meal or a fancy holiday dinner.

Prep Time30

Cook Time45

Total Time1 15

Course: Dinner, Side Dish

Cuisine: American

Servings: people

Calories: 439kcal

Author: Veronika Grove

Ingredients

5-6 large Yukon gold potatoes peeled and thinly sliced
3 tablespoons unsalted butter
3 tablespoons all-purpose flour
2 cups milk
1 teaspoon salt
½ teaspoon garlic powder
½ teaspoon onion powder
½ teaspoon dried oregano
½ teaspoon dried thyme
¼ teaspoon black pepper
2 cups Gruyere cheese grated
½ cup Parmesan cheese grated

Instructions

Preheat the oven to 400˚F, grease a 9x13-inch baking pan and set aside.
Peel the potatoes and thinly slice them using a mandoline. Then set aside.
In a saucepan, melt 3 tbsp butter on a medium heat. Add 3 tbsp all-purpose flour and whisk for one minute until well combined. Then add 2 cups milk and whisk until all the ingredients are well combined and there are no clumps.
Then add the seasoning (1 tsp salt, ½ tsp garlic powder, ½ tsp onion powder, ½ tsp dried oregano, ½ tsp dried thyme, ¼ tsp black pepper).
Bring the mixture to simmer and continue cooking constantly stirring for about 10 minutes or until the sauce thickens and coats a spoon.
When done, remove from the heat and add 1 ½ cups grated Gruyere cheese and ¼ cup grated Parmesan cheese. Fold it in until the cheese is melted and well combined.
Take the prepared pre-greased baking pan. Evenly layer half of the sliced potatoes and pour over half of the cheesy sauce. Then layer the rest of the potatoes over and pour the rest of the cheesy sauce on top, making sure it’s all evenly spread and covers the potatoes.
Sprinkle over the rest of the cheese (½ cup grated Gruyere cheese and ¼ cup grated Parmesan cheese).
Cover with foil and bake at 400˚F for 25 minutes. Then uncover and continue baking for another 20-25 minutes or until the potatoes are tender andthe cheese gets golden/brown color.
When done, take the baking pan out of the oven. At first, it might look like the sauce it too liquid and the butter separates. Just let it sit on the counter for 10 minutes, until the sauce sets and binds everything together.
Serve and enjoy!

Notes

To have evenly sliced potatoes, I prefer to use a mandoline slicer. If you don’t have one, you can do it with a sharp knife. Just try to cut the potatoes thin and evenly.
This recipe is all about sauce! It’s rich, creamy, and flavorful. When you make it, just make sure you simmer it enough to get the right consistency, so it won’t be too liquid or thick. It should be thick enough to coat a spoon but not too thick to create a “ribbon”.
If you have any leftovers (I doubt you will!), you can transfer them to an air-tight container and keep in the fridge for 2-3 days.

Nutrition