3 pounds fresh spinach
3 Tablespoons unsalted butter
2 Tablespoons flour
1 cup milk
1 Tablespoon heavy cream
1/4 teaspoon nutmeg
1 teaspoon kosher salt
1/8 teaspoon freshly ground black pepper.
Remove the stems from the spinach leaves. Discard any leaves that are discolored or tough. Soak the spinach in a small bowl of cold water, stirring to dislodge sand and grit. Change the water at least two or three tims to ensure that the spinach is absolutely clean. Thoroughly dry the spinach in a salad spinner or on paper towels.
To make the bechamel, melt 2 tablespoons of the butter in a non-reactive saucepan over low heat. Sift in the flour and stir with a wooden spoon until the flour is completely incorporated into the butter. Cook gently, stirring, for 5 minutes. Don't let the flour brown. Remove the roux from the heat and whisk in the milk. Return to a boil, whisking constantly, and cook 2-3 minutes longer. Cover and set aside while you cook the spinach.
In a large pot, melt 1 tablespoon butter. Cook the spinach, stirring until wilted, and simmer 1 minute longer if necessary to remove any excess water from the spinach.
Pulse the cooked spinach in a food processor to make a coarse puree.
Add the pureed spinach to the saucepan with the bechamel. Bring to a simmer and stir in the heavy cream, nutmeg, salt, pepper, and remaining butter.
