Ultra-Creamy Cheesy Potato Gratin with Crispy Golden Crust Step-by-step instructions

Before you start

Before beginning, gather all your ingredients and equipment. Preheat the oven to 375 degrees Fahrenheit (190 degrees Celsius) and lightly grease a white fluted baking dish with butter. Scrub the potatoes thoroughly to remove any dirt, then peel them if desired, though leaving the skins on adds a rustic touch.

Set up a mandoline slicer or sharpen a chef's knife to ensure thin, even slices. Mince the garlic cloves and measure out the heavy cream and shredded cheese so everything is ready for assembly.

Instructions

Slicing and Arranging

1. 1Slice and Arrange Potatoes
   Preheat the oven to 375 degrees Fahrenheit (190 degrees Celsius). Peel the Yukon Gold potatoes and slice them very thinly, about one-eighth of an inch thick, using a mandoline slicer or a sharp chef's knife. Arrange the potato slices tightly in a concentric spiral pattern, starting from the outer edge of the greased white fluted baking dish and working your way toward the center, ensuring the slices overlap slightly.
   Look for The potatoes should form a tight, uniform spiral.
   Tip Do not rinse the potato slices, as the starch helps thicken the sauce.

At the end of the slicing and arranging phase, the potatoes should form a beautiful, tight, and uniform spiral filling the fluted baking dish.

The slices should be packed closely together with minimal gaps, which prevents them from floating once the liquid is added. The dish is now ready for the warm cream infusion.

Cream and Cheese Assembly

2. 2Warm the Garlic Cream
   In a small saucepan over medium-low heat, combine the heavy cream and minced garlic. Heat the mixture gently for about three to five minutes until warm and fragrant, but do not let it come to a boil. This warming process allows the garlic flavor to infuse thoroughly into the cream before baking.
   Look for The cream should be warm and highly fragrant.
   Tip Watch the pan closely to ensure the cream does not boil over.
3. 3Pour Cream and Add Cheese
   Slowly and evenly pour the warm garlic-infused cream over the arranged spiral of potato slices in the baking dish, making sure the cream seeps down into all the crevices. Scatter the shredded cheese evenly over the top of the potatoes, covering the surface completely to ensure a uniform, bubbly crust.
   Look for The cheese should form a complete, even layer.
   Tip Grate the cheese from a block for the smoothest melt.

After pouring the warm garlic cream and scattering the cheese, the cream should submerge the lower portions of the potatoes, leaving the very tops slightly exposed. The shredded cheese should form a generous, even blanket across the entire surface, ready to melt and seal in the steam during the initial baking stage.

Bake and Broil Completion

4. 4Bake and Broil
   Cover the baking dish tightly with aluminum foil and bake in the preheated oven for 45 minutes. Remove the foil and continue baking for another 15 minutes, or until the potatoes are completely tender when pierced with a knife. Turn on the oven broiler for the last two to three minutes to get the cheese bubbling and golden brown.
   Look for The top should be deeply browned and bubbling.
   Tip Watch the broiler closely to prevent the cheese from burning.

When the baking is complete, the gratin will be bubbling vigorously around the edges, and the cheese topping will have transformed into a deep golden-brown, crispy crust. The cream will have thickened into a rich, velvety sauce, and a knife should slide effortlessly through the center of the potato layers.

Common mistakes

One common mistake is using milk or half-and-half instead of heavy cream, which lacks the necessary fat content to withstand the long baking time and will curdle, resulting in a watery, grainy sauce.

Another error is slicing the potatoes too thickly or unevenly, which leads to some pieces remaining hard while others turn to mush. Finally, do not rush the baking process; the potatoes must be covered initially to steam and cook through before baking uncovered to crisp the top.

How to tell it’s done

To determine if the gratin is perfectly cooked, insert a sharp paring knife or a toothpick directly into the center of the dish. It should slide in with absolutely no resistance, indicating the potato layers are completely tender.

The edges should be bubbling with thickened cream, and the cheese topping should be deeply browned and crispy. Let the gratin rest for 10 minutes before serving to allow the sauce to set.