8 potatoes, cubed
140g fresh spinach leaves
1/4 cup butter
1 onion, sliced
1 teaspoon minced garlic
3 tablespoons all-purpose flour
1/2 teaspoon salt
1 cup milk
1 cup heavy cream
2 cups shredded Gouda cheese
Preheat an oven to 200 degrees C. Combine the potatoes and spinach in a 23 x 33cm baking dish; set aside.
Melt 3 tablespoons of butter in a saucepan over medium-low heat. Stir in the onion, and cook until dark brown, about 15 minutes. Stir in the garlic and flour; cook 1 minute more. Season with salt, and stir in the milk and cream. Bring to a simmer over medium heat; cook and stir until the sauce has thickened, about 10 minutes. Stir in 3/4 of the Gouda cheese until melted, and pour over the potatoes.
Cover the potatoes with aluminium foil, and bake in the preheated oven 30 minutes. Uncover, and cook 20 minutes more, then sprinkle with the remaining Gouda cheese, return to the oven, and bake until the potatoes are tender and the cheese is bubbly, about 10 minutes more.
Cut up some chives and sprinkle over dish.
Aluminium foil helps keep food moist, ensures it cooks evenly, keeps leftovers fresh, and makes clean-up easy.