Plain, healthy, boring spinach is completely transformed into something magical in this creamy spinach gratin dish.

I never knew I could fall in love with a side dish before. I mean, side dishes are so…so…I don’t know…sidey. And admittedly, I’m not great at pulling out the stops for side dishes for your average weeknight dinner.

Usually at our dinner table we’ve got the main meal, a vegetable of sorts and I’m always good for a starch, like bread or biscuits. Simple and boring, I’m afraid.

White bowl of creamy spinach with a spoon in it.

But for Thanksgiving? Well, that requires a whole new level of side dishes and this spinach gratin is the side dish of my dreams.

I never knew a dish with spinach as the sole focus could taste so creamy and dreamy and delicious.

The flavor of the dish is built at the beginning with the sautéed onions and garlic and is later compounded with simple ingredients like a hint of nutmeg, cream, Parmesan cheese and salt and pepper.

White casserole dish of creamy cooked spinach topped with cheese.

The spinach absorbs all of the flavors and melds into something completely decadent and delicious. I mean, really, spinach? Plain, healthy, boring spinach? It is completely transformed into something magical here.

This will be a forever staple on my holiday table – Thanksgiving, Christmas, you name it, it will be there. I loved it, my husband loved it, the kids loved it (gasp!), and our dinner guests loved it.

That pretty much means it will probably appear weekly from here on out. I’ll create holidays just to make this. (Thanks, Kim, for passing on the recipe to me!)

Forkful of creamy cooked spinach over a bowl full of the same spinach gratin.

One Year Ago: Thanksgiving Dinner: The Pie
Two Years Ago: Coconut Chicken Curry


Creamy Spinach Gratin

5 stars (4 ratings)


  • 4 tablespoons butter
  • 4 cups minced yellow onions, about 2 large onions
  • 2 cloves garlic, finely minced
  • ¼ cup flour
  • ¼ teaspoon grated nutmeg
  • 1 cup heavy cream
  • 2 cups milk
  • 3 pounds frozen chopped spinach, defrosted (5 (10-ounce) packages)
  • 1 cup freshly grated Parmesan or Parmigiano Reggiano cheese
  • 1 tablespoon kosher salt, or 1/2 tablespoon table salt
  • ½ teaspoon freshly ground black pepper
  • ½ cup grated Gruyere, Swiss or Parmesan cheese


  • Preheat the oven to 425 degrees F.
  • Melt the butter in a large skillet (12-inch) over medium heat. Add the onions and saute until translucent, about 10 minutes. Add the garlic and sauté until fragrant, about 2 more minutes. Add the flour and nutmeg and cook, stirring, for 2 more minutes. Add the cream and milk and cook, stirring often and quickly, 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 9X13-inch or similar sized baking dish and sprinkle the remaining 1/2 cup Parmesan and the Gruyere (or Swiss or Parmesan, if using) on top. Bake for 20 minutes until hot and bubbly. Serve hot.


Liquid: it is really important to squeeze as much liquid from the spinach as possible or the gratin will be watery. The best method I’ve found is to put the spinach in a large dishtowel, roll up the towel, and twist the ends to wring out the liquid. Use those muscles and get rid of all the water!
Serving: 1 Serving, Calories: 358kcal, Carbohydrates: 22g, Protein: 17g, Fat: 24g, Saturated Fat: 15g, Cholesterol: 76mg, Sodium: 1317mg, Fiber: 6g, Sugar: 8g

Recipe Source: from Kim M., a reader, who adapted it from Barefoot Contessa Parties