Cheesy Au Gratin Potatoes

I was originally asked to make Au Gratin/Scalloped Potatoes to serve with ham at a mid-December holiday party for about 30 people. I didn’t really have a tried and true recipe to call on so I went to “the google” and found an almost overwhelming number of options. I zeroed in on one (adding a few tweaks) that sounded the most tasty on Gimme Some Oven. The outcome was a combination of melt-in-your-mouth potato cheesiness and a slightly crunchy browned topping that everyone loved.

So, let’s get cooking!

Cheesy Au Gratin Potatoes

INGREDIENTS:

  • 3 tablespoons butter
  • 1 small white or yellow onion, peeled and thinly sliced
  • 4 large garlic cloves, minced
  • 1/4 cup all-purpose flour
  • 1 cup chicken stock or vegetable stock
  • 2 cups milk (I recommend 2% or whole milk)
  • 1 1/2 teaspoons Kosher salt
  • 1/2 teaspoon black pepper
  • 2 teaspoons fresh thyme leaves, divided
  • 4 pounds Yukon Gold Potatoes, sliced into 1/8-inch rounds
  • 2 cups freshly-grated sharp cheddar cheese*, divided (feel free to add more cheese if you’d like)
  • 1 cup freshly-grated gruyere cheese, divided
  • 1/2 cup freshly-grated Parmesan cheese, plus extra for serving
Ingredients for Cheesy Au Gratin Potatoes

DIRECTIONS:

  1. Preheat oven to 400°F.  Grease a 9 x 13-inch baking dish with cooking spray; set aside.
  2. Melt butter in a large sauté pan over medium-high heat.  Add onion, and sauté for 4-5 minutes until soft and translucent.  Add garlic and sauté for an additional 1-2 minutes until fragrant.  Stir in the flour until it is evenly combined and cook for 1 more minute.  Gradually pour in the stock, and whisk until combined.  Add in the milk, salt, pepper, 1 teaspoon thyme, and whisk until combined.  Continue cooking for an additional 1-2 minutes until the sauce just barely begins to simmer around the edges of the pan (avoid letting it come to a boil) and thickens.  Then remove from heat and set aside.
  3. Spread half of the sliced potatoes in an even layer on the bottom of the pan.  Top evenly with half of the cream sauce.  (I strained out all of the onions and added them here too.)  Then sprinkle evenly with 1 cup of the shredded cheddar cheese, half of gruyere and half of the parmesan cheese.  Top evenly with the remaining sliced potatoes, the other half of the cream sauce, and the remaining cheeses.
  4. Cover the pan with aluminum foil and bake for 30 minutes.  The sauce should be nice and bubbly around the edges.  Then remove the foil and bake uncovered for 25-30 minutes, or until the potatoes are cooked through.
  5. Transfer the pan to a cooling rack, and sprinkle with the remaining teaspoon of thyme and extra Parmesan.  Serve warm.

Pop these in the oven and let the melting magic begin!

Cheesy Au Gratin Potatoes!

Hope that you enjoy this classic side dish that goes great with ham, steaks, chicken, etc. Dig in!