Go Back
A freshly baked golden-brown spinach and feta breakfast casserole in a rustic dish.

Spinach and Feta Breakfast Casserole

Print Recipe Pin Recipe
Prep Time 15 minutes
Cook Time 35 minutes
Servings: 8
Course: Breakfast
Cuisine: Mediterranean
Calories: 145
Ingredients Method Notes

Ingredients
  

  • * 10 large eggs
  • * 1/2 cup milk or plain Greek yogurt
  • * 1 tablespoon olive oil
  • * 1 small yellow onion finely diced
  • * 3 cloves garlic minced
  • * 6 oz fresh baby spinach roughly chopped
  • * 1 cup feta cheese crumbled
  • * 1/2 teaspoon sea salt
  • * 1/4 teaspoon freshly cracked black pepper
  • Optional Add-Ins:
  • * 1/4 cup sun-dried tomatoes thinly sliced
  • * 1/4 cup Kalamata olives sliced
  • The Base & Aromatics
  • 1 tbsp olive oil
  • 1 small yellow onion finely diced
  • 3 cloves garlic minced
  • 6 oz fresh baby spinach roughly chopped
  • 1/2 tsp sea salt
  • 1/4 tsp freshly cracked black pepper
  • The Eggs & Cheese
  • 10 large eggs
  • 1/2 cup whole milk or plain Greek yogurt for extra protein
  • 1 cup feta cheese crumbled (divided)
  • Optional Add-ins For extra flavor
  • 1/4 cup sun-dried tomatoes thinly sliced
  • 1/4 cup Kalamata olives sliced

Method
 

  1. Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish with
  2. olive oil or cooking spray.
  3. Heat the olive oil in a large skillet over medium heat. Add the yellow
  4. onion and cook for 4-5 minutes until soft and translucent.
  5. Stir in the minced garlic and sauté for 1 minute until fragrant.
  6. Add the chopped baby spinach to the skillet in batches. Stir until just
  7. wilted (about 2-3 minutes).
  8. Remove from heat. Transfer the spinach and onion mixture to a strainer
  9. and press out the excess moisture.
  10. In a large bowl, whisk together the eggs, milk (or Greek yogurt), sea salt,
  11. and black pepper for 1-2 minutes until completely smooth and a bit frothy.
  12. Spread the drained spinach mixture across the bottom of your greased baking
  13. dish. Sprinkle half of the crumbled feta over the top.
  14. Pour the egg mixture evenly into the pan. Scatter the remaining feta
  15. cheese and any optional add-ins evenly over the top.
  16. Bake for 30-35 minutes until the center is set and the edges are lightly
  17. golden brown.
  18. Remove from the oven and let rest for 5 minutes before slicing.
  19. Preheat your oven to 375°F (190°C) and grease a 9x13-inch baking dish.
  20. Sauté the diced onion in olive oil for 4 to 5 minutes until soft.
  21. Add the minced garlic and cook for 1 minute, then stir in the spinach and cook until wilted.
  22. Transfer the spinach mixture to a strainer and press down firmly to remove excess liquid.
  23. In a mixing bowl, vigorously whisk the eggs, milk (or Greek yogurt), salt, and pepper for 1 minute until frothy.
  24. Layer the squeezed spinach across the bottom of the prepared baking dish.
  25. Sprinkle with half of the crumbled feta cheese.
  26. Pour the whisked egg mixture over the top.
  27. Scatter the remaining feta cheese and any optional add-ins evenly over the eggs.
  28. Bake for 30 to 35 minutes until the center is set. Let rest for 5 minutes, then slice and serve.

Notes

  • Prevent sogginess: Squeeze all excess water out of the cooked spinach before adding it to the dish.
  • Avoid dry texture: Do not overbake the eggs; remove from the oven when the center has a slight jiggle.
  • Make-ahead option: Assemble the night before, cover, refrigerate, and bake fresh in the morning.
  • Storage: Keep refrigerated in an airtight container for up to 4 days, or freeze for up to 2 months.
  • Reheating: Microwave on medium power for 45 to 60 seconds to avoid drying out the eggs.