Spinach Gratin
From Lucy's recipe collection. Photographed from her binder of favorites curated over 30+ years.
Ingredients
- 4 tablespoons unsalted butter (1/2 stick)
- 4 cups chopped yellow onions (2 large)
- 1/4 cup all-purpose flour
- 1/4 teaspoon grated nutmeg
- 1 cup heavy cream
- 2 cups milk
- About 3 pounds frozen chopped spinach, defrosted (5 10-ounce packages)
- 1 cup freshly grated Parmesan cheese
- 1 tablespoon kosher salt
- 1/2 teaspoon freshly ground black pepper
- 1/2 cup grated Gruyère cheese
Method
- Preheat the oven to 425 degrees.
- Melt the butter in a heavy-bottomed sauté pan over medium heat. Add the onions and sauté until translucent, about 15 minutes. Add the flour and nutmeg and cook, stirring, for 2 more minutes. Add the cream and milk and cook until thickened.
- Squeeze as much liquid as possible from the spinach and add the spinach to the sauce. Add 1/2 cup of the Parmesan cheese and mix well. Season to taste with the salt and pepper.
- Transfer the spinach to a baking dish and sprinkle the remaining 1/2 cup Parmesan and the Gruyère on top. Bake for 20 minutes, or until hot and bubbly. Serve immediately.
Notes from the kitchen
- Serves 8