Savory cooked spinach in a creamy Parmesan white sauce, topped with more nutty salty Parmesan and baked to comforting side dish perfection. This Cheesy Creamed Spinach Gratin Casserole is perfect for holiday meals, or even for a nice Sunday family dinner.
Cheesy Creamed Spinach Gratin Casserole is one of those recipes I cut out of a magazine years ago. I’ve made many times, especially for family holiday gatherings. I love it. Several of my relatives love it, and I always get compliments from those that try it.
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Simple Veggie Side Dish
Spinach is a bitter green, especially when cooked. But the creamy white sauce and Parmesan help offset the bitterness, as does the sweet cooked onion. Making for a nicely balanced great simple veggie side dish.
None of the steps to make this Cheesy Creamed Spinach Gratin Casserole are difficult or too time consuming; however, there are a few steps to the dish.
Cheesy Creamed Spinach Gratin Casserole Notes and Tips
The biggest tip I can give you, is to make sure you squeeze all the liquid out of the cooked spinach. This will make sure that you are left with simply cooked yummy spinach, and your gratin won’t be too runny.
And, as always, feel free to use whatever milk makes you happy. I prefer whole milk for this recipe; it’s nice and thick and rich without being too heavy. But 2% or maybe even a mixture of half and half and 2% would be lovely. Plant-based Almond milk or soy milk would work as well for this recipe.
The other time saver, if you want to try it, is to cook the onion in the microwave. I have had several readers tell me they don’t have microwaves, so I didn’t include the microwave instructions in the recipe write-up, but it’s a time-saving and calorie saving hint for anyone who might want to try it.
Instead of sautéing onions on the stove in oil or butter, soften them in the microwave. Place the chopped or sliced onion in a microwave-safe bowl, along with about a tablespoon or two of water. Cover the bowl with a plate. Microwave the covered bowl for 3 to 4 minutes. The onions will be soft and translucent. And, they are recipe ready!
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Cheesy Creamed Spinach Gratin Casserole Recipe
Cheesy Creamed Spinach Gratin Casserole
- 2 pounds fresh spinach stemmed, washed, and drained
- 1 ½ cups milk
- 2 tablespoons olive oil or light tasting oil of your choice
- ½ medium yellow onion finely diced
- 2 tablespoons all-purpose flour
- ¼ teaspoon kosher salt
- Pinch freshly ground black pepper
- Pinch ground cayenne
- 1 ¼ cups freshly grated Parmesan cheese divided use
- Heat the oven to 350° F.
- Spray a 1 ½ quart shallow baking dish with non stick cooking spray.
- Fill a large pot about halfway with lightly salted water, and bring to a boil over high heat. Add the cleaned spinach to the boiling water in large handfuls, adding more spinach as it wilts. When all the spinach is in the pot, cook (blanch) for 1 minute. Drain the cooked spinach in a colander while running cold water over it to cool it. Once it has cooled, drain all the water out, and squeeze the spinach with your hands to remove as much liquid as possible. Coarsely chop the drained spinach.
- Heat the milk in a small saucepan until hot. Place the oil in a medium saucepan, and heat over medium heat. Once the oil is hot, add the onion, and cook until translucent and softened but not colored, about 5 minutes.
- Stir in the flour, salt, pepper, and cayenne and cook, stirring constantly, for 2 minutes. Slowly stir in the milk, raise the heat to medium-high, and cook, stirring frequently, until the sauce bubbles and thickens, about 5 minutes.
- Add 1 cup of the Parmesan cheese to the sauce, and stir until the cheese is melted and thoroughly combined.
- Remove the pan from the heat, and stir in the chopped spinach, mixing well. Taste for salt and pepper, adding more if necessary. Pour the spinach mixture into the prepared baking dish, sprinkle the remaining ¼ cup Parmesan on top, and bake until the gratin nicely browned, about 35 minutes. Let cool a few minutes before serving.