I keep a dedicated recipe file for potluck-ready dishes, and within that I have a special section for brunch ideas. This Easy Egg and Spinach Casserole is one of my favorites. It bakes up beautifully, making an impressive centerpiece on a buffet or brunch table when you lift the cover and reveal the golden top. It also serves a crowd — rich, cheesy, and satisfying, a single generous slice will please even hearty appetites.
This casserole can be vegetarian if you choose vegetarian-friendly cheeses. Some cheeses use animal-derived rennet in production, so check labels if you’re serving vegetarians. In my experience, many pre-shredded supermarket Cheddar and Swiss varieties are suitable. The result is a crowd-pleaser that appeals to both vegetarians and meat-eaters, making it an excellent choice for mixed gatherings.
Unlike many quiches or frittatas, this recipe uses a bit of flour to help thicken and bind the mixture, which is useful given the generous amounts of cheese and butter. Make sure the flour is well incorporated into the beaten eggs — small lumps are acceptable, but break up any larger ones. I like to use a stand mixer to beat the eggs and distribute the flour, then finish by folding in the spinach and cheeses by hand so the larger ingredients keep their texture.
The casserole holds together nicely and slices cleanly once it has a short rest after baking. If you’d like variations, the recipe is forgiving: swap cheeses to taste, use fresh spinach instead of frozen (cooked and drained thoroughly), or replace the onion with shallots or a dash of onion or garlic powder. Just be mindful of very strong cheeses — if you choose Gruyère, sharp Cheddar, or Parmesan, reduce the total cheese by at least 1/2 cup to avoid overpowering the dish.
Easy Egg and Spinach Casserole
3.6 from 218 votes
Ingredients
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7 large eggs
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1/2 cup onion, fine dice
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1/4 cup all-purpose flour
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1 package (10oz) frozen chopped spinach, thawed & drained
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1 package (16oz) cottage cheese, small curd
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1 1/2 cups Cheddar cheese, shredded
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1 1/2 cups Swiss cheese, shredded
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1/4 cup butter, melted
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1 teaspoon garlic salt
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salt & pepper
Directions
- Preheat oven to 350° F (175° C). Grease a large casserole or a 9×13-inch baking dish with cooking spray.
- In a large bowl, beat the eggs. Add the flour, garlic salt, and salt & pepper to taste. Beat until the flour is thoroughly incorporated.
- Squeeze the thawed spinach to remove excess water, then add it to the bowl along with the melted butter, diced onion, cottage cheese, Cheddar, and Swiss. Mix well.
- Pour the mixture into the prepared baking dish and spread evenly.
- Bake uncovered about 45 minutes, until the top is golden brown and the egg mixture is set. Let rest 10 minutes before slicing and serving.
Notes
- Make sure the flour is well incorporated into the eggs for an even texture.
- Swap Cheddar and Swiss for Mozzarella, Colby, or Monterey Jack if preferred. If you choose very flavorful cheeses (Gruyère, sharp Cheddar, or Parmesan), reduce the total cheese by at least 1/2 cup.
- To use fresh spinach, cook about 1 lb briefly in a sauté pan or blanch, then drain and cool thoroughly before adding.
- Shallots or leeks work well instead of onion, or omit the onion and use 1 teaspoon onion powder or garlic powder.
I typically bake this casserole for 45 minutes, but egg-based dishes can be sensitive to variables like baking dish material, cheese fat content, and oven calibration. Start checking around 35 minutes: when the eggs are fully set and no longer jiggly, the casserole is done. It may need an extra ten minutes in some ovens, so keep an eye on it and remove when the top is nicely browned and the center feels firm.