Want an easy, vegetarian breakfast casserole that feeds a crowd? A make-ahead egg strata recipe that gets baked while everyone is enjoying their second cup of coffee? This spinach and mushroom breakfast strata is the best. With fresh spinach, sauteed mushrooms and sweet, chewy sun-dried tomatoes, this simple spinach and mushroom recipe is always a winner.
Table of Contents
Breakfast Strata Is An Easy, Make-Ahead, Feeds A Crowd, Recipe
With Christmas fast approaching and family rapidly descending, it pays to have a plan for Christmas morning. A workable plan. Not “I think I’ll make eggs benedict for 12 people”. Enter the breakfast strata — a simple make ahead meal that’s hearty, eggy, cheesy, vegetable-laden and that you make the night before! Bake it the next morning – simple. This spinach and mushroom egg strata is entertaining nirvana!
Spinach and Mushroom Breakfast Strata Ingredients
- Sun-Dried Tomatoes
- Gruyere Cheese
- Parmesan Cheese
- Mustard Powder
- Cayenne Pepper
- Kosher Salt
- Stale Sourdough or Italian Bread
Since this is a vegetarian breakfast casserole, and I live mostly amongst carnivores, serving this egg strata recipe with a rash of bacon, or porky sausages is only logical. If you really have a crowd coming, I’d recommend doubling this recipe and serving it beside this easy holiday ham – which takes all of 10 minutes to prep.
This is a relatively simple recipe, but it pays to follow the directions.
Tips For Vegetarian Breakfast Casserole
- The key to making it work is to make sure that there’s no excess liquid from the vegetables being mixed in. So after you’ve sauteed the mushrooms, make sure you drain them very well (mushrooms are 90% water – and can easily turn your strata to soup if you’re not careful.)
- The same thing goes for the spinach — whether you’re using fresh or frozen, make sure that you’ve removed all of the excess liquid. I like to squeeze it in a clean dish towel, but you can also transfer to a mesh sieve and press on the spinach with a wooden spoon (or clean hands) to press out the excess liquid.
The rest is easy peasy.
Assembling Vegetarian Breakfast Casserole
- In a medium bowl, combine the eggs, milk, cayenne, dry mustard, garlic salt, black pepper and kosher salt and whisk well to combine.
- Add the cheeses and stir.
- Spray a casserole dish with vegetable spray.
- Add about 1/3 of the stale cubes of bread.
- Layer with about half of the vegetable mixture.
- Top with 1/3 of the custard.
- Add another 1/3 of bread cubes, followed by the rest of the vegetables and 1/3 of the egg custard.
- Top the breakfast strata with a final layer of bread, and the rest of the egg and cheese custard.
- Press lightly on the breakfast strata with your hands to ensure the custard starts getting soaked up by the bread.
- Top with a little extra gruyere and parmesan cheese.
- Cover and refrigerate overnight.
This spinach and mushroom breakfast strata bakes up beautifully the next morning while your sipping your coffee and watching the kids tear into presents. This is also ideal for a festive holiday brunch, serve it with plenty of bellini and Bloody Marys’ to amp up the merriment!
More Breakfast Strata Recipes:
- Sweet Potato and Apple Breakfast Strata
- Hatch Chile Breakfast Strata
- Sausage Apple Strata with Cheddar Pecan Streusel
More Make Ahead Breakfasts To Feed A Crowd:
Tried this recipe? Leave a rating and review.
Your comments and shares are invaluable to me and the thousands of readers who use this site daily. If you've made the recipe, leave a star rating and review. We want to hear how you liked it.
We'd love it if you shared the recipe with your friends on social media!
Spinach and Mushroom Breakfast Strata
- 12 ounces crimini or button mushrooms thinly sliced
- 1 teaspoon butter
- 8 ounces fresh spinach or 1 box frozen chopped spinach thawed
- ⅓ cup sun-dried tomatoes chopped
- ½ cup gruyere cheese + extra for sprinkling
- ¼ cup parmesan cheese + extra for sprinkling
- 5 large eggs
- 1 ½ cups milk
- 1 teaspoon mustard powder
- ⅛ teaspoon cayenne pepper
- ¾ teaspoon garlic salt
- ½ teaspoon black pepper
- ¾ teaspoon kosher salt divided
- 4 cups stale italian or sourdough bread crusts removed, cut into 1/2″ cubes
- In a non stick skillet with a lid, heat over medium high heat until pan is hot. Add sliced mushrooms and 1/4 teaspoon kosher salt to the skillet and stir once or twice. Put the lid on the pan and let the mushrooms give off their liquid for a minute. Continue to check the mushrooms and stir every 30 seconds or so until all of their liquid has been given up and mushrooms are slightly browned. Transfer the mushrooms to a medium bowl.
If you’re using fresh spinach
- Add the butter to the pan and saute the fresh spinach until it just wilts. Transfer the spinach to a fine mesh sieve and press on the spinach with the back of a spoon to squeeze out all the excess liquid. Chop the spinach on a cutting board then add it to the mushrooms
If you’re using frozen spinach
- Place spinach in a clean dish towel and squeeze out all the liquid and add it to the mushrooms.
- Toss the sun-dried tomatoes with the spinach and mushrooms, set aside.
- In a medium bowl whisk together the eggs, milk, mustard powder, cayenne pepper, garlic salt, black pepper and remaining 1/2 teaspoon kosher salt. Stir in the cheeses.
- Spray a 4-5 cup casserole dish with nonstick spray. Add 1/3 of the bread cubes. Sprinkle with half of the vegetable mixture. Pour 1/3 of the egg and cheese mixture over the vegetables. Top with 1/3 of the bread cubes and the remaining half of the vegetables. Top with the remaining bread and pour the rest of the egg/cheese mixture evenly over the bread.
- Use your hands to press the bread lightly into the mixture to soak up the egg custard.
- Top with a sprinkling of gruyere and parmesan cheese. Cover and refrigerate for 8 hours or overnight.
- Take the strata out of the refrigerator half an hour before you’re ready to bake. Preheat the oven to 350 degrees. Bake strata for 45-50 minutes until puffed, browned and bubbly. Let it rest for 10 minutes before serving.