Spinach Gratin

By merehodge

Ingredients

• 4 tablespoons unsalted butter (1/2 stick)
• 4 cups yellow onion, chopped
• 1/4 cup all-purpose flour
• 1/4 teaspoon nutmeg, grated
• 1 cup heavy cream
• 2 cups milk
• 3 pounds frozen spinach, defrosted, chopped
• 1 cup freshly grated Parmesan cheese
• 1 tablespoon kosher salt
• 1/2 teaspoon freshly ground black pepper
• 1/2 cup Gruyére cheese, grated

Preparation

Step 1

Preheat oven to 425º
Melt the butter in a heavy-bottomed sauté pan over medium heat. Add onion and sauté until translucent, about 15 min. Add the flour and nutmeg and cook, stirring, for 2 more min. Add the cream and milk and cook until thickened.
Squeeze as much liquid as possible from spinach and add it to the sauce. Add 1/2 cup Parmesan cheese and mix well. Salt and pepper to taste. Transfer spinach to baking dish and sprinkle the remaining 1/2 cup Parmesan and Gruyére on top. Bake 20 min. or until hot and bubbly. Serve immediately.