Scalloped Potatoes

Preheat the oven to 350°F. Grease a 9x13-inch casserole dish and set aside.

In a large saucepan, melt 1/4 cup salted butter over medium-low heat. Add the 1 diced large yellow onion and 2 minced garlic cloves; cook until the onion begins to soften, about 3 to 4 minutes.

Stir in 1/4 cup all-purpose flour and cook for 2 minutes more to cook out the raw flour taste.

Combine 2 cups milk and 1 cup chicken broth. Gradually add the liquid mixture to the flour mixture, whisking continuously until smooth after each addition. It will be thick at first; continue adding liquid slowly while whisking.

Once all liquid is added, increase heat to medium and bring to a boil while whisking. Stir in 1/2 teaspoon of the salt and 1/8 teaspoon of the pepper. Let the sauce boil for 1 minute to thicken.

Layer 1/3 of the 3 pounds of sliced potatoes in the prepared dish. Season the layer with 1/4 teaspoon salt and 1/8 teaspoon pepper. Pour 1/3 of the cream sauce evenly over the top.

Repeat the layers two more times (potatoes, salt/pepper, sauce), ending with the sauce on top. You should have used the remaining salt and pepper.

Cover the dish tightly with aluminum foil and bake for 45 minutes.

Uncover and bake for an additional 35-45 minutes until golden brown and potatoes are tender. Optionally, broil for 3-4 minutes for extra browning.

Allow the potatoes to rest for at least 20 minutes before serving to allow the sauce to set.