Low-fat potato casserole

Ingredients:

• 1.3 kg potatoes, peeled and thinly sliced
• 2 tbsp (30 g) butter, plus extra for greasing the pan
• 2 tbsp. flour
• 1 cup skim milk (1%), room temperature
• 1 cup whole milk, room temperature
• 1/4 tsp. grated nutmeg
• 1/4 tbsp. grated gruyere cheese

Preparation:

1. Preheat oven to 175°C. Lightly grease a 3-quart baking dish with butter.
2. Bring a large saucepan of salted water to a boil, add the potatoes, and cook until tender, 8-10 minutes. Then drain and return the potatoes to the pan.
3. Meanwhile, melt 2 tablespoons (30 g) butter in a saucepan over medium heat. Stir in the flour with a wooden spoon to form a paste. Cook, stirring, until the paste begins to simmer, about 1 minute. Gradually whisk in the milk and cook, whisking constantly, until thickened, about 3 minutes. Remove from heat and stir in 1/2 teaspoon pepper, 1 1/2 teaspoons salt, and nutmeg. Pour the sauce over the potatoes and toss gently.
4. Transfer the potato mixture to the prepared baking dish and sprinkle with grated cheese. Bake until the potatoes are heated through, about 10 minutes. Turn the oven to broil and broil the casserole until the top is golden brown, about 5 minutes. Let the casserole rest for 10 minutes, then serve.