Creamed Spinach Gratin

I made this the first time for Thanksgiving 2005 for my ILs. Huge hit!

Creamed Spinach Gratin

1 tablespoons unsalted butter, plus more for the dish
1 clove garlic, halved
5 shallots, thinly sliced crosswise
5 10-ounce boxes frozen spinach, thawed
8 ounces low-fat cream cheese, at room temperature
2 cup skim milk
1 cup grated Gruyère or Swiss cheese
1 teaspoon kosher salt
1/2 teaspoon black pepper
1 teaspoon ground nutmeg

Heat oven to 375° F. Rub the sides and bottom of a buttered 8-inch baking dish with the garlic; discard garlic.

In a skillet, over medium heat, melt the butter. Add the shallots and cook until softened, 5 to 7 minutes.

Squeeze the spinach to remove any excess liquid. In a large bowl, combine the spinach, cream cheese, milk, cheese, salt, pepper, nutmeg, and shallots. Transfer to dish. Bake, uncovered, until bubbling and lightly golden, about 25 minutes.