Bon Appétit: Fresh Spinach Gratin with Parmesan and Blue Cheeses

I was going through an old cooking magazine, and I came across this recipe for spinach with blue cheese.  I remembered how I made a broccoli casserole with blue cheese a while ago, and it was delicious.  So I quickly concluded that this would also be delicious.  And I was correct.  Don't mind the picture above; you are correct, there is blue cheese only on the left side.  Someone in my family (::cough cough:: dad ::cough cough::) doesn't have an appreciation for blue cheese the way the rest of us do.  Also, I felt like the casserole needed something crunchy, and what's better than a couple handfuls of fried onions?  Nothing.  Well, perhaps bacon.

Fresh Spinach Gratin with Parmesan and Blue Cheeses

From Bon Appétit magazine, January 2004

7 tablespoons unsalted butter, divided
5 (9-to 10-ounce) packages fresh spinach leaves
1¼ pounds onions, chopped

¼ cup all-purpose flour
½ teaspoon ground nutmeg
1½ cups whole milk

1 cup whipping cream
1 cup (packed) freshly grated Parmesan cheese, divided
2 teaspoons sea salt
½ teaspoon ground black pepper
½ cup crumbled blue cheese
French fried onions, for garnish

Butter a 10- to 12-cup shallow baking dish. Melt 1½ tablespoons butter in heavy large pot over high heat. Add 1 package spinach. Toss until volume is slightly reduced, about 1 minute.  Add 1½ more packages spinach; toss until wilted but still bright green, about 2 minutes longer. Transfer to colander set over large bowl. Repeat with 1½ tablespoons butter and remaining spinach. Turn all spinach in colander, pressing to release all liquid.

Melt 4 tablespoons of butter in same heavy large pot over medium heat. Add onions; sauté until beginning to soften, about 10 minutes. Mix in flour and nutmeg. Stir 2 minutes to cook flour (do not brown). Whisk in milk and cream. Cook until sauce thickens and boils, whisking often, about 5 minutes. Mix in ½ cup Parmesan, salt, and pepper. Mix in spinach. Transfer to dish. Sprinkle with remaining Parmesan and blue cheese. (Can be made 6 hours ahead. Cover; chill.)

Preheat oven to 425°F.  Bake gratin about 15 minutes (or 20 minutes if refrigerated).  Top with onions and bake another 5 minutes, or until bubbling and brown on top.

Makes 8 servings