Cheesy Potatoes Au Gratin With Gruyere

4.08 from 14 votes

With thinly sliced potatoes and a creamy Gruyère sauce, cheesy potatoes au gratin is a comfort food side dish you’ll make again and again!

Prep Time20

Cook Time1

Total Time1 20

Course: Side Dish

Cuisine: American

Keyword: cheesy potatoes au gratin with gruyere, potatoes au gratin

Servings: servings

Calories: 362kcal

Preheat the oven to 350 degrees.
In a small sauce pan, melt butter. Once melted add flour with a fork – whisking together.
Next, whisk in milk.
Cook sauce on low until smooth and boiling, whisking until thickened.
Add in salt, pepper , and dry mustard and stir well.
Reduce heat to low and stir in 1 cup of the cheese.
Place a half of the sliced potatoes in a lightly greased 1.5 quart casserole dish (8×8 or 9×9 will work)
Pour half of the cheese sauce over potatoes.
Add a second layer of potatoes and the rest of the cheese sauce to the top of that layer
Sprinkle the remaining 1/2 cup of cheese on top.
Sprinkle the top with paprika.
Bake at 350 degrees, uncovered for 1 hour.

Use a mandoline slicer for the potatoes: It’s important that the potatoes are all sliced to the same thickness, otherwise, you’ll have some that are mushy and others that are hard and taste raw when you pull the gratin out of the oven.
Make the topping crispy: You can turn on the broiler in the last few minutes of cooking time to make the top layer crispy and browned.
Let it rest before serving: Let the dish rest before serving so it doesn’t “run” when you slice.