Spinach and Mushroom Breakfast Strata

Spinach and mushroom strata in a casserole dish.

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.

sauteing mushrooms

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!


  • Mushrooms – you can use white button mushrooms, cremini or an assortment of wild mushrooms.
  • Butter – for sauteeing the vegetables.
  • Spinach – I use fresh baby spinach. You can use frozen, but it needs to be completely defrosted and all the liquid needs to be squeezed out of it.
  • Sun-Dried Tomatoes – I recommend the ones in olive oil as they’re more tender.
  • Gruyere Cheese – a French cheese similar to Emmenthaler, Swiss or Jarlsberg. It’s a good melting cheese.
  • Parmesan Cheese – Preferably grated fresh from a wedge.
  • Eggs – can’t make a strata without breaking a few eggs.
  • Milk – for the custard in the breakfast strata.
  • Mustard Powder – to season the strata.
  • Cayenne Pepper – for a hint of spice and tingle.
  • Kosher Salt – I recommend Diamond Crystal kosher salt as it’s lighter and flakier with less sodium by volume than Morton’s
  • Pepper – fresh ground will give you the best flavor.
  • Stale Sourdough or Italian Bread – Get a loaf of bakery bread a few days before making this strata, so it will get stale.
pressing out excess liquid from spinach

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.

sun dried tomatoes for egg strata recipe
combining veg for Spinach and Mushroom Breakfast Strata

This is a relatively simple recipe, but it pays to follow the directions.  

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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.
making custard for vegetarian breakfast cassesrole.
Layering egg strata recipe

The rest is easy peasy.

Assembling  Vegetarian Breakfast Casserole

  1. In a medium bowl, combine the eggs, milk, cayenne, dry mustard, garlic salt, black pepper and kosher salt and whisk well to combine.
  2. Add the cheeses and stir.
  3. Spray a casserole dish with vegetable spray.
  4. Add about 1/3 of the stale cubes of bread.
  5. Layer with about half of the vegetable mixture.
  6. Top with 1/3 of the custard.
  7. Add another 1/3 of bread cubes, followed by the rest of the vegetables and 1/3 of the egg custard.
  8. Top the breakfast strata with a final layer of bread, and the rest of the egg and cheese custard.
  9. Press lightly on the breakfast strata with your hands to ensure the custard starts getting soaked up by the  bread.
  10. Top with a little extra gruyere and parmesan cheese.
  11. Cover and refrigerate overnight.
Vegetarian Breakfast cassserole hot from the oven.

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!  

spooning out the spinach and mushroom egg strata More Breakfast Strata Recipes: 

More Make Ahead Breakfasts To Feed A Crowd:

Spinach and Mushroom Breakfast Strata on a plate with a fork.

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3.70 from 39 votes

Spinach and Mushroom Breakfast Strata

One of the simplest ways to entertain overnight guests is with a delicious strata for breakfast.  It assembles in no time and is ready to bake while you’re having your coffee the next morning!
Author: Lisa Lotts
Course Breakfast
Cuisine American
Keyword eggs, mushrooms, spinach, sun dried tomatoes
Prep Time 30 minutes
Cook Time 50 minutes
Servings 6


  • 12 ounces crimini or button mushrooms thinly sliced
  • 1 teaspoon butter
  • 8 ounces fresh spinach or 1 box frozen chopped spinach thawed
  • 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
  • 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.


This recipe can be doubled.


Calories: 251kcal | Carbohydrates: 20g | Protein: 17g | Fat: 11g | Saturated Fat: 5g | Cholesterol: 159mg | Sodium: 911mg | Potassium: 684mg | Fiber: 2g | Sugar: 7g | Vitamin A: 4960IU | Vitamin C: 5.7mg | Calcium: 315mg | Iron: 2.9mg


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  1. Judith R. says:

    5 stars
    I added 1 tbsp of hot sauce to the egg mixture and used stale sourdough. Outstanding! Will make again for Christmas brunch.

  2. Earline hammer says:

    I would like to see comments from someone who has actually MADE this. How can you get 4 stars from people who are just thinking about it!

  3. Deb Jackson says:

    This recipe sounds delicious! I’m going to try it for a Bridal Brunch in the North Carolina mountains.
    All the girls are going to do yoga, in the garden, and then brunch on the back porch!
    What would you suggest I serve with this veggie strata?
    All of the guests are quite healthy eaters.
    With many thanks.

    1. Well, my go to with this strata has always been a baked ham — feeds a crowd and its very economical. Along with a green salad, fresh fruit and plenty of sparkling wine — that sounds like a party to me.

  4. How big is a casserole dish?

    1. I think I used a 7×9″, but look through your casserole dishes and see what it will fit into comfortably. The strata should fill to about a 2″ depth.

  5. Can it be frozen before baking? Would you have to defrost before putting it in the oven?

    1. That’s an interesting question, I’ve never tried it. My initial inclination would be to bake it and THEN freeze it — reheat it in a low oven (300°) AFTER DEFROSTING.

  6. Oh that looks like such a fun breakfast for a crowd – love it!
    Jane x

  7. Michelle @ Vitamin Sunshine says:

    This looks so delicious! Love that it can be made ahead for a special event breakfast.

    1. We all need a few of those make-ahead dishes in our back pocket, don’t you think?

  8. 5 stars
    You always come up with the most beautiful and tasty recipes. I’m saving this recipe for next time that I have guests.

    1. You are very kind! Thank you so much — I hope you enjoy it!

  9. This sounds and looks much better than my boring breakfast porridge! Pinning to try later

    1. We make strata when we’re having a group over for breakfast or brunch, it’s easy and can be made ahead!

  10. Everyday Sarah Jane says:

    The flavors in this sound unbelievable! …and the addition of sun dried tomatoes?? Seriously, so good and so yum!

    1. Yes, the sun-dried tomato adds a sweet bite and it’s so good!

  11. Lauren Gaskill | Making Life Sweet says:

    This looks amazing! I am definitely making this for my next ladies’ brunch!! Pinning!

    1. It’s one of our favorites. Please let me know how you like it!