Kitchen Monki will be closing its doors soon, and the site will go offline.
If you would like an export of all your recipe data, please email [email protected] from the email associated with your account.
Welcome to Kitchen Monki's Consumer Site. Go to Corporate Home »

Au Gratin Potatoes

Print recipe & shopping list
Au Gratin Potatoes
Submitted by:
Makes: 4 servings adjust
Delicious and versatile side dish! Can completely change the taste just by changing the cheese used.



Step 1

Preheat oven to 400 degrees. Spray a 2 quart casserole with cooking spray.


  • 3 tablespoons Unsalted Butter
  • 3 tablespoons All-Purpose Flour
  • 12 teaspoon Kosher Salt
  • 2 cups Milk

Step 2

In a medium-size saucepan, melt butter over medium heat. Mix in the flour and salt, and stir constantly with a whisk for one minute. Stir in milk. Cook until mixture has thickened. NOTE: Heating the milk in the microwave until very warm will make the sauce thicken much faster.


  • 1 12 cups Shredded Cheddar Cheese, or cheese of your choice
  • 12 teaspoon Dijon Mustard
  • dash Sriracha, just a couple drops

Step 3

Stir in cheese all at once, and continue stirring until melted, about 30 to 60 seconds. Stir in dijon mustard and sriracha. Taste and correct seasoning, if needed.


  • 4 Russet Potatoes

Step 4

Scrub potatoes and slice into 1/4 inch slices. NOTE: Don't slice the potatoes too far in advance of assembly or they will turn brown. I used a mandolin and sliced one potato per layer. This went super quick.


  • 1 medium Onion, chopped
  • Salt and Pepper, to taste

Step 5

Place a layer of 1/4 of the sliced potatoes into prepared casserole dish. Sprinkle evenly with 1/4 of the chopped onion, season lightly with salt and pepper. Top with 1/4 of the cheese sauce.

Step 6

Repeat layers with remainder of the potatoes, onions and cheese sauce being sure to end with a layer of the cheese sauce.

Step 7

Tightly cover the casserole with aluminum foil that has been sprayed with cooking spray to prevent sticking. Bake in preheated oven for 1 1/2 hours or until heated and bubbly and potatoes are cooked through. NOTE: Poke a knife or skewer into the casserole. There should be no resistance.

Step 8

Optional: Uncover casserole and sprinkle with a little additional cheese. Return to the oven until the cheese is melted and the potatoes are just starting to brown on top.

Step 9

Allow to cool 10-15 minutes before serving.
Kitchen Monki sign up