Spinach Tomato Feta Breakfast Casserole brings tender eggs, juicy tomatoes, and tangy feta to the breakfast table. The spinach adds a savory bite without weighing it down. A thin layer of mozzarella gives the top a soft, golden finish. Slice it for brunch, or keep a few portions ready for busy mornings.
Why I Love This Recipe
This is the kind of breakfast that does most of its work in the oven. The feta supplies plenty of flavor, so the eggs need only simple seasoning. Cooking the spinach first keeps the casserole tender without leaving water in the bottom of the dish.
- Easy to portion: The rested egg bake cuts into servings that hold together.
- Fresh flavor: Tomatoes balance the salty feta and rich eggs.
- No bread needed: The eggs form the base and bind the vegetables together.
- Useful leftovers: Individual portions are simple to warm up later.
What You’ll Need
- Servings: 8
- Prep Time: 20 minutes
- Cook Time: 50 minutes, including the skillet cooking
- Rest Time: 10 minutes
- Total Time: 1 hour 20 minutes
- Oven Temperature: 350°F (175°C)
- Baking Dish: 9×13-inch glass baking dish
Ingredients
- 1 tablespoon plus 1 teaspoon olive oil, divided
- 1/2 cup finely diced onion
- 1 garlic clove, minced
- 8 ounces fresh baby spinach, roughly chopped
- 10 ounces cherry tomatoes, halved and patted dry
- 12 large eggs
- 3/4 cup whole milk
- 1 teaspoon dried oregano
- 1/4 teaspoon fine salt
- 1/2 teaspoon ground black pepper
- 6 ounces feta cheese, crumbled
- 1 cup (4 ounces) shredded low-moisture mozzarella
- 1 tablespoon finely chopped fresh parsley
Feta varies in saltiness. The modest amount of added salt leaves room for its briny flavor. Use low-moisture mozzarella rather than fresh mozzarella, which releases more water.
Tools You Need
- 9×13-inch rectangular glass baking dish
- Large skillet
- Large mixing bowl and whisk
- Measuring cups and spoons
- Cutting board and knife
- Broad serving spatula
- Instant-read thermometer
How to Make Spinach Tomato Feta Breakfast Casserole
Cook the vegetables first, then combine, bake, and give the casserole a short rest.
Step 1: Prepare the Dish and Vegetables
Preheat the oven to 350°F (175°C) with a rack in the middle.
Grease an unlined 9×13-inch glass baking dish with 1 teaspoon olive oil.
Finely dice enough onion to make 1/2 cup, mince 1 garlic clove, roughly chop 8 ounces baby spinach, and halve 10 ounces cherry tomatoes.
Pat the tomato halves dry with a clean towel.
Step 2: Cook Off the Spinach Moisture
Heat the remaining 1 tablespoon olive oil in a large skillet over medium heat.
Add 1/2 cup finely diced onion and cook for 3 minutes, stirring, until softened.
Stir in 1 minced garlic clove and cook for 30 seconds.
Add 8 ounces chopped baby spinach in batches and stir for 2 minutes, until wilted and any visible liquid has cooked away.
Take the skillet off the heat and let the vegetables cool for 5 minutes while you whisk the eggs.
Step 3: Whisk the Eggs
Whisk 12 large eggs, 3/4 cup whole milk, 1 teaspoon dried oregano, 1/4 teaspoon fine salt, and 1/2 teaspoon ground black pepper in a large bowl until evenly blended.
Keep the whisking gentle; you want a smooth mixture rather than a thick cap of foam.
Step 4: Assemble the Casserole
Stir the cooled spinach mixture, 10 ounces halved cherry tomatoes, and 6 ounces crumbled feta cheese into the egg mixture until evenly distributed.
Pour everything into the greased 9×13-inch glass baking dish and spread out the vegetables.
Scatter 1 cup (4 ounces) shredded low-moisture mozzarella in a thin, even layer across nearly the whole top.
Step 5: Bake Until Just Set
Bake uncovered for 40–45 minutes, until the edges are lightly golden and the center is set without a liquid wobble.
Check the middle with an instant-read thermometer; the egg mixture should reach 160°F (71°C). If the top colors before the center sets, loosely cover with foil for the remaining baking time.
Remove the dish from the oven and immediately sprinkle 1 tablespoon finely chopped parsley over the melted cheese.
Rest for 10 minutes before cutting. The casserole will settle slightly as it rests.
Step 6: Cut and Serve
Cut the rested casserole into 8 portions and lift each portion from the bottom with a broad spatula.
Serve warm, keeping the tender egg, vegetables, feta and cheese topping together. Add toast or fresh fruit alongside if you would like a larger breakfast.
Why This Recipe Works (Quick Science)
Egg proteins link together as they heat, turning the liquid mixture into a soft, sliceable bake. Milk adds moisture, while the feta stays in little creamy pockets rather than melting into stretchy strands. Mozzarella supplies the smooth melted top.
Spinach and tomatoes both carry water. Wilting the spinach until the skillet is dry and blotting the tomatoes limits that extra moisture. Pulling the casserole when the center is just set helps keep the eggs tender. The short rest lets the structure settle before slicing.
Common Mistakes to Avoid
- Leaving water in the spinach: Cook away visible liquid before adding it to the eggs.
- Using wet tomatoes: Blot the cut surfaces so their juices do not dilute the mixture.
- Adding too much salt: Feta and mozzarella both contribute salt.
- Baking until the center feels hard: Check for a set center and the correct temperature instead. Overbaked eggs can become rubbery.
- Cutting immediately: Let the casserole rest for 10 minutes so portions release more neatly.
Substitutions and Variations
Frozen spinach can work. Thaw 8 ounces frozen chopped spinach, squeeze it very dry, and add it to the cooked onion and garlic just long enough to heat through. It will give a denser spinach presence than the fresh version.
Grape tomatoes can replace the cherry tomatoes by weight. Halve and blot them the same way. For a sharper herb flavor, replace the parsley with the same amount of finely chopped dill.
What to Serve With Spinach Tomato Feta Breakfast Casserole
Toast adds a crisp contrast to the soft eggs. Fresh fruit keeps the meal light, while roasted breakfast potatoes make it more filling. These are optional sides; the casserole is flavorful enough to serve on its own.
Make-Ahead Tips
For the best texture, cook the spinach mixture the night before and refrigerate it separately. Whisk and assemble the casserole when you are ready to bake.
You can also bake the casserole ahead, cool it promptly, and refrigerate individual portions. Reheat only what you plan to serve. Avoid moving a cold glass dish straight into a hot oven; follow the dish maker’s thermal-shock guidance.
Leftovers and Storage
Refrigerate leftovers in shallow airtight containers within 2 hours of baking. Keep refrigerated for 3–4 days.
Microwave a refrigerated portion, loosely covered, in short bursts until the center reaches 165°F (74°C). Start with 45–60 seconds, then continue as needed. Let it stand briefly and check the middle.
For longer storage, freeze cooled portions individually for up to 2 months for best quality. Thaw in the refrigerator overnight before reheating. A little moisture after thawing is normal for an egg bake with vegetables.
Macros Information
Estimated per serving, based on 8 servings and excluding optional sides:
- Calories: 255
- Protein: 19 g
- Carbohydrates: 7 g
- Fat: 17 g
- Saturated Fat: 7 g
- Fiber: 1 g
- Sugar: 4 g
- Sodium: 570 mg
These are estimates and will vary with the cheeses, milk, and exact ingredient sizes used.
Frequently Asked Questions (FAQ)
Q: Does this casserole contain bread?
A: No. Eggs hold the spinach, tomatoes, and feta together without a bread or potato base.
Q: Can I use frozen spinach?
A: Yes. Thaw it completely and squeeze it very dry. Follow the amount and method in the substitutions section.
Q: Why is there liquid under my casserole?
A: Wet spinach or very juicy tomatoes can release extra water. Overbaking can also make eggs tighten and squeeze out moisture.
Q: How do I know the middle is cooked?
A: It should be set rather than liquid, and an instant-read thermometer in the center should read 160°F (71°C). Check the egg mixture rather than a tomato pocket.
Q: Can I use a different milk?
A: The same amount of 2% milk works well. Avoid sweetened milk alternatives, which change the flavor.
Q: Will the feta melt completely?
A: No. Feta softens but keeps small creamy pieces. The mozzarella makes the melted layer on top.
Q: Can I halve the recipe?
A: Yes. Halve all ingredients and use a greased 8-inch square baking dish. Start checking at 25 minutes and cook until the center reaches 160°F (71°C).
Q: Can I freeze individual servings?
A: Yes. Cool and package them separately, then freeze for up to 2 months for best quality. Thaw in the refrigerator before reheating.
Q: Is this good for meal prep?
A: Yes. Refrigerate the cut portions for 3–4 days and reheat each one until the center reaches 165°F (74°C).
Final Thoughts
Spinach Tomato Feta Breakfast Casserole makes a savory breakfast with simple ingredients and plenty of flavor. Keep the vegetables dry, watch the center as it bakes, and give it a short rest before slicing. Leave a comment and share what you served alongside it. Happy cooking!