I keep a dedicated file of potluck-friendly recipes, and within that collection I have an entire section for brunch dishes. This Easy Egg and Spinach Casserole is one of my favorites. It bakes up beautifully and makes a dramatic presentation—perfect for buffets or a shared brunch. The casserole is cheesy, rich, and very filling; a single serving will satisfy even a hearty appetite. It also stretches well, so it’s a great choice when you need to feed a crowd.
This casserole is vegetarian-friendly if you choose cheeses made without animal rennet. Many supermarket pre-shredded Cheddar and Swiss varieties are suitable for vegetarians, but if you’re cooking for a vegetarian guest, double-check ingredient labels. In my experience, both vegetarians and meat-eaters enjoy this dish, so it’s a reliable pick for mixed company.
This recipe uses a small amount of flour to help the casserole set and hold together, which distinguishes it from many quiches or frittatas. The flour helps bind the generous amounts of cheese and butter in the mixture. When mixing, be sure the flour is fully incorporated into the beaten eggs; a few tiny lumps are fine, but break up any larger pieces. I usually use a stand mixer to beat the eggs and work in the flour, then fold in the spinach and cheeses by hand so the texture stays even and the larger ingredients aren’t overmixed.
Easy Egg and Spinach Casserole
Rated 3.6 out of 5 from 218 votes
Ingredients
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7 large eggs
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1/2 cup onion, finely diced
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1/4 cup all-purpose flour
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1 package (10 oz) frozen chopped spinach, thawed and drained
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1 package (16 oz) 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 and freshly ground black pepper, to taste
Directions
- Preheat the oven to 350° F (175° C). Grease a large casserole dish or a 9×13-inch baking pan with cooking spray or a light coating of butter.
- In a large bowl, beat the eggs until smooth. Add the flour, garlic salt, and salt and pepper to taste, then beat again to fully incorporate the flour into the eggs.
- Squeeze any excess liquid from the thawed spinach, then add it to the bowl along with the melted butter, diced onion, cottage cheese, Cheddar, and Swiss. Stir until the mixture is evenly combined.
- Pour the mixture into the prepared baking dish and smooth the top.
- Bake uncovered for about 45 minutes, or until the top is golden brown and the egg mixture is set. Remove from the oven and let rest for 10 minutes before cutting and serving.
Notes
- Make sure the flour is well blended into the eggs before adding the other ingredients; this helps the casserole hold its shape.
- You can swap Cheddar and Swiss for milder cheeses such as Mozzarella, Colby, or Monterey Jack. If you use stronger cheeses like Gruyère, sharp Cheddar, or Parmesan, reduce the total cheese by at least 1/2 cup to avoid overpowering the dish.
- If you prefer fresh spinach, substitute about 1 pound. Sauté or briefly blanch the leaves, then drain and cool thoroughly before adding to the mixture.
- Shallots or leeks make good alternatives to onion for a subtler flavor.
- If you omit the onion, consider adding 1 teaspoon of onion powder or 1 teaspoon of garlic powder to maintain savory depth.
I find a 45-minute bake time works well, but egg-based dishes can be sensitive to slight differences in oven performance, baking dish material, and the cheeses you use. Start checking the casserole around 35 minutes; if the eggs are just set and the center is firm, it’s ready. If the center still jiggles, give it another 5–10 minutes until the eggs are fully set. Let the casserole rest for a few minutes before serving so it finishes setting and is easier to slice.