Ingredients
Equipment
Method
- Heat the oven to 375°F.
- Use 1 tablespoon of the butter to grease a 9x13-inch baking dish.
- Melt the remaining 4 tablespoons butter in a 3-quart saucepan over medium heat.
- Add the onion and cook for 4 to 5 minutes until softened.
- Add the garlic and cook for 30 seconds.
- Stir in the flour and cook for 1 minute.
- Gradually whisk in the milk, salt, and pepper.
- Bring the mixture to a gentle simmer and cook, whisking, for 3 to 5 minutes until thickened enough to coat a spoon.
- Remove the saucepan from the heat and stir in 1 1/2 cups of the cheddar until melted.
- Arrange one-third of the potatoes in the prepared dish and spread one-third of the cheese sauce over them.
- Repeat the potato and sauce layers twice, finishing with the sauce.
- Sprinkle the remaining 1/2 cup cheddar on top.
- Cover the dish tightly with foil and bake for 45 minutes.
- Remove the foil and bake for 25 to 35 minutes, until the top is golden and a knife slides easily into the potatoes in the center.
- Let the potatoes rest for 15 minutes before serving.
Notes
For even cooking, slice the potatoes consistently to 1/8 inch thick. Refrigerate leftovers for 3 to 4 days; freezing is not recommended because the cheese sauce may separate. For a lactose-free option, use lactose-free milk and a suitable lactose-free cheddar.
