“Scalloped potatoes are good, but Potatoes au Gratin are even better! Everything is better with cheese!” – April Ferre
Potatoes au Gratin
- 3 Pounds Yukon Gold Potatoes
- 1 Medium Onion
- 3 Tablespoons Butter
- 3 Tablespoons Flour
- 2 Cups Milk
- 1 Teaspoon Dry Mustard
- 1 1/2 Cups Cheese (See Note)
- Salt & Pepper to Taste
- Preheat oven to 400 degrees.
- Wash and slice potatoes and onions into 1/8-inch slices. A mandolin slicer is helpful for this. There is no need to peel the potatoes. Combine in a 9×13-inch baking dish.
- Melt butter in a medium saucepan over medium heat. When butter starts to sizzle, add flour and cook, stirring constantly for 2 to 3 minutes. Add milk slowly, while whisking over medium heat until smooth and well combined. Add dry mustard and continue to cook until thick and bubbly.
- Remove from heat and add cheese, stirring until melted and well combined. Pour over potatoes.
- Cover with foil and bake for 60 minutes. Remove foil and bake another 20 to 30 minutes until golden brown.
You can use any type or combinations of cheeses that you desire. I personally like to use 1 cup cheddar cheese and 1/2 cup Gruyere cheese.