Scalloped Potato Gratin

This lighter version of classic scalloped potatoes is the perfect side dish for your holiday or family meals. Thin slices of buttery Yukon gold potatoes are layered with reduced-fat cheddar and baked in a subtly seasoned milk sauce infused with thyme and nutmeg. The result is a creamy, savory, and satisfying dish that delivers all the comfort of traditional gratins, but with fewer calories and fat.

Why You’ll Love This Recipe

Uses minimal butter and fat-free milk for a lighter profile
Still rich and flavorful with cheese and warming spices
Easy to prepare ahead and bake fresh before serving
A great alternative to heavier potato casseroles

Ingredients

Olive oil spray (or cooking spray)
6 medium Yukon gold potatoes, peeled and sliced into 1/8-inch rounds (about 2 lbs 4 oz)
2 tablespoons light butter, melted
Salt and freshly ground black pepper, to taste
1/2 teaspoon garlic powder
3 ounces shredded reduced-fat cheddar cheese (about 3/4 cup)
1 cup fat-free milk
1 bay leaf
Pinch of freshly grated nutmeg
2 teaspoons fresh thyme leaves, or 1/2 teaspoon dried thyme

Equipment

11 x 7-inch baking dish
Mandoline or sharp knife (for even potato slices)
Small saucepan
Mixing bowls

Instructions

Preheat the Oven
Preheat your oven to 425°F (220°C). Lightly coat an 11 x 7-inch baking dish with olive oil spray.
Prepare the Potatoes
In a large mixing bowl, toss the thinly sliced potatoes with the melted butter, garlic powder, salt, and freshly ground black pepper until evenly coated.
Layer the Potatoes
Transfer half the potatoes into the prepared baking dish, spreading them into an even layer. Sprinkle 1/4 cup of the grated cheddar evenly over the top. Layer the remaining potato slices over the cheese.
Make the Sauce
In a small saucepan, combine the milk, bay leaf, thyme, and nutmeg. Bring the mixture just to a boil over medium heat, then remove from the heat and discard the bay leaf.
Assemble and Bake
Pour the warm milk mixture evenly over the potatoes. Scatter the remaining shredded cheese over the top. Bake the gratin, uncovered, for 45 to 50 minutes, or until the potatoes are tender and the top is golden and bubbly.
Serve
Let the dish rest for about 10 minutes before serving to allow the sauce to thicken slightly.

Helpful Tips

A mandoline ensures even, thin slices—ideal for a tender and uniform gratin. For safety, always use a cut-resistant glove.
Yukon gold potatoes offer a buttery flavor and creamy texture, but red or russet potatoes may also be used.
Gruyere is an excellent cheese substitute if you’re looking for a nutty, rich flavor.
This recipe can be assembled in advance. Cover tightly with plastic wrap and refrigerate. Bake just before serving.
Leftovers store well in the refrigerator or freezer. Thaw overnight and reheat in the oven for best results.

Serving Suggestions

This gratin pairs beautifully with roasted chicken, grilled steak, or festive holiday mains. It’s a crowd-pleasing, comforting side that complements vegetables or proteins.