Ingredients
- Fresh Spinach: 2 pounds, baby spinach or mature spinach, thoroughly washed and dried. Fresh spinach is the star of the show, providing the earthy base for our gratin. Baby spinach is tender and requires minimal prep, while mature spinach offers a more robust flavor – both work beautifully. Ensure the spinach is thoroughly washed to remove any grit and completely dried. Excess moisture will make the gratin watery. You can use frozen spinach in a pinch (see ingredient notes below), but fresh spinach offers a superior texture and flavor.
- Heavy Cream: 1 ½ cups. Heavy cream is the foundation of the rich and velvety sauce that defines Spinach Gratin. It provides the luxurious creaminess and richness that coats the spinach perfectly. For a truly decadent gratin, heavy cream is essential. You can experiment with half-and-half or milk for a lighter version (see ingredient notes), but heavy cream provides the classic texture and flavor.
- Gruyère Cheese: 1 ½ cups, grated. Gruyère cheese is the quintessential cheese for a classic Spinach Gratin. It melts beautifully, creating a smooth and nutty flavor with a slightly sweet and earthy undertone. Gruyère provides a complex and sophisticated cheese flavor that elevates the dish. It also browns beautifully under heat, creating a gorgeous golden crust.
- Parmesan Cheese: ½ cup, grated, plus extra for topping. Parmesan cheese adds a salty, savory, and umami-rich depth to the gratin. It complements the Gruyère perfectly, adding another layer of cheesy complexity. Use freshly grated Parmesan for the best flavor and melting quality. We use it both within the gratin mixture and as a final topping for extra browning and flavor.
- Yellow Onion: 1 medium, finely chopped. Yellow onion forms the aromatic base of the gratin, providing a subtle sweetness and savory depth. Finely chopping the onion ensures it cooks through evenly and blends seamlessly into the creamy sauce.
- Garlic: 3-4 cloves, minced. Garlic adds a pungent and aromatic kick that enhances the savory flavors of the spinach and cheese. Freshly minced garlic is always best for the most intense and vibrant flavor.
- Butter: 4 tablespoons, unsalted butter. Butter is used to sauté the onion and garlic, building flavor from the very beginning. It also adds richness to the sauce. Unsalted butter allows you to control the salt level of the dish.
- All-Purpose Flour: 2 tablespoons. All-purpose flour acts as a thickening agent for the creamy sauce. It helps to create a smooth and stable sauce that coats the spinach effectively.
- Nutmeg: ¼ teaspoon, freshly grated if possible. Nutmeg adds a warm, subtly sweet, and slightly spicy aromatic note that is a classic pairing with spinach and creamy sauces. Freshly grated nutmeg offers a more intense and nuanced flavor than pre-ground nutmeg.
- Salt: To taste. Salt is crucial for enhancing the flavors of all the ingredients. Season generously but gradually, tasting as you go.
- Black Pepper: Freshly ground, to taste. Freshly ground black pepper adds a pungent and aromatic bite that complements the savory flavors of the gratin.
Instructions
- Prepare the Spinach: If using fresh spinach, ensure it is thoroughly washed and dried. If using mature spinach with large stems, remove the tough stems. Roughly chop the spinach if using mature spinach; baby spinach can be left whole or roughly chopped if desired. Set aside.
- Sauté Onion and Garlic: Melt butter in a large skillet or Dutch oven over medium heat. Add the finely chopped onion and sauté for 5-7 minutes, until softened and translucent. Then, add the minced garlic and cook for another minute, until fragrant. Be careful not to burn the garlic. Sautéing the onion and garlic in butter builds a flavorful base for the gratin.
- Make the Cream Sauce: Sprinkle the all-purpose flour over the sautéed onions and garlic in the skillet. Cook for 1 minute, stirring constantly, to create a roux. This helps thicken the sauce. Gradually whisk in the heavy cream, ensuring there are no lumps. Continue whisking and cooking over medium heat until the sauce thickens slightly and is smooth, about 3-5 minutes. Season the sauce with salt, black pepper, and freshly grated nutmeg. Taste and adjust seasoning as needed.
- Wilt the Spinach: Add the fresh spinach to the skillet with the cream sauce in batches. Stir and toss the spinach until it wilts down and is incorporated into the sauce. This may take a few minutes, as spinach wilts down significantly. If using frozen spinach, add it to the sauce after thawing and squeezing out excess moisture.
- Stir in Cheese (Most of It): Remove the skillet from the heat. Stir in the grated Gruyère cheese and grated Parmesan cheese (reserving some Parmesan for topping), until the cheeses are melted and evenly incorporated into the spinach mixture. The cheese will melt into the hot spinach mixture, creating a rich and cheesy base.
- Transfer to Baking Dish: Pour the spinach and cheese mixture into a greased 9×13 inch baking dish or oven-safe gratin dish. Spread the mixture evenly in the dish.
- Top with Remaining Cheese: Sprinkle the reserved grated Parmesan cheese evenly over the top of the spinach mixture in the baking dish. This creates a cheesy crust on top of the gratin. If using breadcrumbs, sprinkle breadcrumbs over the cheese at this stage.
- Bake Until Golden and Bubbly: Bake in the preheated oven at 375°F (190°C) for 20-25 minutes, or until the gratin is heated through, bubbly around the edges, and the cheese topping is melted and golden brown. The baking time may vary slightly depending on your oven and baking dish. The gratin is ready when it’s heated through, bubbly, and the cheese topping is nicely browned and melted.
- Let Rest and Serve: Remove the Spinach Gratin from the oven and let it rest for a few minutes before serving. Resting allows the gratin to set slightly and cool down enough to be enjoyed comfortably. Serve hot as a side dish.
Nutrition
- Serving Size: one normal portion
- Calories: 350-450
- Fat: 25-35 grams
- Carbohydrates: 10-15 grams
- Fiber: 3-5 grams
- Protein: 10-15 grams