Classic Potato Gratin, GF

By MaryEllen

Techniques vary for this dish. Some recipes have you gently boil the cream first to reduce it a little, but the danger here is that it can break. Other recipes have you layer raw potatoes right in the casserole dish and top with hot cream. I like to simmer the potatoes briefly in the half-and-half on top of the stove. It just seems to bring the potatoes and dairy together in a fantastic way that ultimately gives you a super creamy, silky potato gratin.

Note from Robin: Make sure you make a large casserole dish of these. They are AMAZING as leftovers. I put mine into a cast iron pan in a 350 F degree oven for 20 minutes and they came out crispy, and creamy and seriously yummy. So easy to add alongside eggs and bacon, or a salad and you have a meal.

Ingredients

• 1/2 1/2 1/2 tablespoon unsalted butter
• 2 2 2 pounds (910 g) russet potatoes, peeled
• 3 3 3 cups (720 ml) lactose-free half-and-half, such as Organic Valley
• 1 1 1 teaspoon kosher salt
• Freshly ground black pepper
• 1/4 1/4 1/4 teaspoon fresh thyme, optional
• Pinch Pinch freshly ground nutmeg, optional
• 1/4 1/4 1/4 pound (115 g) Gruyere cheese, grated (see Tips)

Preparation

Step 1

Position rack in the middle of the oven. Preheat the oven to 400°F/200°C. Use butter to coat the inside of a 3-quart (2.8 L) shallow casserole dish and set aside.
Cut the potatoes into very thin 1/8-inch (3 mm) slices using a very sharp knife or a mandoline (see Tips). Keep them in rounds, if possible.
Place the potatoes in a wide heavy saucepan (I use a 3-quart/2.8 L) and add the half-and-half, salt, a generous amount of pepper and thyme and/or nutmeg, if using. Bring to a vigorous simmer over medium heat, shaking the pan occasionally, and simmer for 3 minutes.
Carefully pour the mixture into prepared casserole dish. Use a silicone spatula to gently coax the potatoes and liquid into an even layer. Sprinkle the cheese evenly over the top.
Bake for about 35 to 45 minutes or until the potatoes are tender when pierced with a knife and the top is golden and bubbling. The mixture might look a little loose, but don’t worry, it will firm up upon cooling. Place casserole on a rack and cool for at least 15 minutes to allow the gratin to achieve its maximum potato perfection. Serve warm or even at room temperature.

Tips

Cutting the potatoes as thin as recommended is a very important step. Pull out a ruler if you have to, to make sure they are thin enough or they will not cook properly. The beauty of a mandoline is that you can set it to the desired thickness and just got to town, knowing that all of your potatoes will be perfectly cut. You could also use a food processor fitted with the appropriately sized slicing disc.
You could play around with other types of cheese. Emmental or Comté would be good alternative choices. Plain Swiss doesn’t have enough sharpness, in my opinion, but use your own palate as a guide.