When you need a deliciously savory brunch dish that can be made ahead, turn to this Veggie Strata recipe and you will be so glad you did! This prep-ahead breakfast casserole is made with layers of sourdough bread soaked in cheesy egg custard and fresh sauteed vegetables.

a serving of the casserole on a white dish with home fries

My 5-Star Strata Recipe

Have I told you I went by the name “Brunch Spice” for a period of my life as if I was the long-lost sixth Spice Girl? That’s a story for another day, but suffice it to say it was during this time that I baked dozens upon dozens of veggie quiches, batches of hollandaise sauce and learned how to make a mean breakfast strata!

I have already shared another favorite strata recipe from that period, we called it Pigs in the Orchard strata (with apples and sausage) Today’s recipe is a crowd-pleasing vegetarian breakfast casserole that will satisfy both carnivores and non-meat eaters! It is just what to make if you need a main course for a brunch buffet that can be prepped ahead.

What is a strata? A strata is a layered breakfast casserole made with torn or cubed stale bread, egg custard and cheese. It usually has meats, bacon, ham and/or veggies added to it. The casserole is usually assembled and refrigerated in advance.

Veggie Strata Ingredients

the ingredients for the strata with text overlay
  • Veggies: I used a blend of mushrooms, peppers and scallions (green onions). Feel free to improvise with another combination of vegetables if you have a preference for something else (asparagus is in season right now so I highly recommend it!)
  • Unsalted butter: To butter the casserole dish use a generous amount of softened butter. Then I also use it to sautee the veggies. You could of course use olive oil, but butter is more traditional for a strata recipe.
  • Milk: For the egg custard use whole milk. You could also use skim milk with a generous splash of half and half or heavy cream instead (measuring 2 cups total.)
  • Eggs: Eggs are the star of any strata! That said, one of the key tips I learned about making an excellent strata with the best texture is to use more milk than eggs by volume in your formula. This gives the casserole plenty of structure and pillowy lift but is still creamy and not too dense.
  • Seasonings: If you have been a reader here for a while you know I love adding Dijon to my egg dishes. Add to that some more usual suspects: garlic powder, salt and pepper. I also added in a teaspoon of dried oregano. If you want to experiment with other flavors try swapping in another dried herb or dried Italian seasoning instead of oregano or use a teaspoon or two of fresh herbs.
  • Bread: You’ll need a good quality bread. Look for a nice dense deli sourdough bread. You’ll need 9 ounces for this strata recipe. If you’re wondering, an average loaf will be 5 to 6 slices. Once it is cut into cubes it’ll be about 6 cups
  • Cheese: No strata is complete without cheese! You’ll need 6 ounces sharp cheddar cheese. Feel free to swap in another type of cheese if you prefer.

Pro Tip: To get your timing right, you’ll want to pop this breakfast casserole into the oven fifty minutes to one hour before serving the meal. It only takes about 40 minutes to bake but then it has to sit for an additional 15 minutes afterwards.

How To Make Veggie Breakfast Casserole

butter the casserole dish and sauté the veggies

Step 1: Generously Butter A Baking Dish

Butter a 2 ½ quart casserole dish with 1 tablespoon of softened unsalted butter.

Step 2: Saute Veggies

Melt 2 tablespoons butter in a large skillet over medium heat. Add green onions, mushrooms and bell pepper and cook, stirring often until the vegetables are softened, 8 to 10 minutes.

let the veggies cool then make the custard

Step 3: Let Veggies Cool

Scrape the veggies onto a plate to cool.

Step 4: Soak Bread in Egg Custard

Whisk the milk, eggs, mustard, oregano, salt, garlic powder and pepper in a medium bowl. Add in the cubed bread and a cup of shredded cheddar cheese. Stir to combine the bread with the egg custard. Let the break soak up the custard for 15 minutes or more. (See more below about how to make this in advance.)

preheat the oven and assemble the strata, layer by layer

Step 5: Preheat the Oven

Preheat your oven to 350 degrees F.

Step 6: Layer Veggies into The Strata

Layer the strata by adding half of the bread mixture to the casserole dish. Top with half of the veggies. Add the remaining bread and veggies. Top with the remaining 2 ounces (1/2 cup) cheese.

the breakfast casserole baking in the oven

Step 7: Bake Casserole

Bake until the strata casserole is puffed, golden and the egg custard  is set up, 35 to 40 minutes. Let cool 10 to 15 minutes before serving.

oval casserole dish with breakfast casserole

Make Ahead Instructions

To Make two days ahead: Prepare through step four up to 2 days ahead. Keep the sauteed veggies in an airtight container. The bread, egg, milk and cheese mixture can be kept in a separate resealable container in the refrigerator. Re-stir the bread with the custard (it will absorb most of the liquid and break down a lot.) Then assemble and bake as directed.

To Make One day ahead: Assemble the strata and cover it with plastic wrap and refrigerate it up to 12 hours to 1 day in advance. Simply remove the wrap before baking.

Serving Suggestions

Leftovers, Freezing and Reheating

Leftovers: Cover the casserole dish with aluminum foil or plastic wrap and refrigerate up to three days. Alternatively, transfer single servings into smaller glass storage containers.

Freezing: Stratas freeze beautifully! Wrap the cooled baked strata and freeze up to 1 month. Thaw and reheat before serving. You can also freeze the assembled unbaked strata. Do not top with the cheese. Cover with foil and bake the frozen strata at 325 degrees for 1 hour. Remove the foil, top with 1/2 cup cheese (2 ounces) and bake until the center is puffed and an instant-read thermometer inserted into the center of the strata registers 165 degrees F, 30 to 40 minutes.

To Reheat the leftovers: Place a sheet of foil over the casserole dish and place in a preheated oven for 20 to 25 minutes or until hot all the way through. Microwave individual portions, loosely covered with parchment or a paper towel, for 1 minute 10 seconds on high heat.

overhead of the table set with a casserole dish with the strata and a white bowl of home-fried potatoes

Variations To Try

As I mentioned in the ingredient section there is plenty of room to improvise with this veggie breakfast casserole recipe. From the veggies to the cheese, you can experiment and make it your own. Here are some ideas to get you started:

  • Vegetables: Use 1 1/2 cups of other cooked seasonal vegetables depending on what is freshest. Look around at the Farmers’ market and pick out what looks good! To keep it simple blend veggies that cook at relatively the same rate. Or make sure to saute harder veggies (like carrots or sweet potato) separately from softer vegetables like zucchini or asparagus because the former takes a little longer to cook through and soften. Also, note that high water-content veggies (like tomatoes) can make your strata watery so use them in moderation. You only need to wilt greens like spinach or chard for a minute or two before layering into the strata.
  • Cheese: You can use smoked cheese or a spicy cheese like pepper jack to really change the flavor profile of this vegetable breakfast casserole. Parmesan would also be good as would Swiss cheese or gruyere. If you’re in a rush, use pre-shredded cheese but note that the top will not melt as nicely since bagged shredded cheese has starch added.
  • Seasonings: I love me an egg dish with a little pinch of nutmeg, so of course I will always make that recommendation. You can also omit the oregano and instead use fresh chopped herbs like tarragon or fresh basil. White pepper is always good with savory brunch dishes featuring egg, cheese and/or dairy. You can also add a couple of glugs of Tabasco too.

Thanks so much for reading! If you are new here, you may want to sign up for my email newsletter to get a free weekly menu plan and the latest recipes right to your inbox. If you make this recipe, please come back and leave a star rating and review. I would love to hear what you thought!

Happy Cooking! ~Katie

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Veggie Strata Breakfast Casserole


5 Stars 4 Stars 3 Stars 2 Stars 1 Star

5 from 2 reviews

  • Author: Katie Webster
  • Total Time: 1 hour 20 minutes
  • Yield: 6 servings 1x

Description

This Veggie Strata Breakfast Casserole recipe is the perfect make-ahead brunch main course. It is made by layering fresh sauteéd vegetables, cheddar cheese, eggs and sourdough bread then baked until it is puffed and golden.


Ingredients

Units Scale
  • 3 tablespoons softened unsalted butter, divided
  • 4 scallions, sliced
  • 4ounces sliced mushrooms
  • 1/2 cup each diced red and green bell pepper
  • 2 cups whole milk
  • 6 eggs
  • 1 teaspoon Dijon mustard
  • 1 teaspoon dried oregano
  • 3/4 teaspoon salt
  • 1/2 teaspoon garlic powder
  • 1/4 teaspoon ground black pepper
  • 6 slices sourdough bread, cut into cubes (about 6 cups or 9 ounces), crusts removed if desired
  • 6 ounces sharp cheddar cheese, divided

Instructions

  1. Butter a 2 ½ quart casserole dish with 1 tablespoon butter.
  2. Melt the remaining 2 tablespoons butter in a large skillet over medium heat. Add scallions, mushrooms and bell pepper and cook, stirring often until the vegetables are softened, 8 to10 minutes.
  3. Scrape the veggies onto a plate to cool.
  4. Whisk milk, eggs, mustard, oregano, salt, garlic powder and pepper in a medium bowl. Add bread and 4 ounces (1 cup) of cheese and stir to coat the bread. Let sit 15 minutes.
  5. Preheat oven to 350 degrees F.
  6. Layer strata by adding half of the bread mixture to the casserole dish. Top with half of the veggies. Add the remaining bread and veggies. Top with the remaining 2 ounces (1/2 cup) cheese.
  7. Bake until the strata casserole is puffed, golden and the egg custard is set up, 35 to 40 minutes. Let cool 10 to 15 minutes before serving.

Notes

Leftovers: Cover the casserole dish with aluminum foil or plastic wrap and refrigerate up to three days. Alternatively, transfer single servings into smaller glass storage containers.

Freezing: Stratas freeze beautifully! Wrap the cooled baked strata and freeze up to 1 month. Thaw and reheat before serving. You can also freeze the assembled unbaked strata. Do not top with the cheese. Cover with foil and bake the frozen strata at 325 degrees for 1 hour. Remove the foil, top with 1/2 cup cheese (2 ounces) and bake until the center is puffed and an instant-read thermometer inserted into the center of the strata registers 165 degrees F, 30 to 40 minutes.

To Reheat the leftovers: Place a sheet of foil over the casserole dish and place in a preheated oven for 20 to 25 minutes or until hot all the way through. Microwave individual portions, loosely covered with parchment or a paper towel, for 1 minute 10 seconds on high heat.

  • Prep Time: 25 minutes
  • Cook Time: 50 mins
  • Category: Brunch
  • Method: Oven

Nutrition

  • Serving Size: 1/6 casserole (about 1 1/4 cup)
  • Calories: 398
  • Sugar: 6 g
  • Fat: 22 g
  • Carbohydrates: 30 g
  • Fiber: 2 g
  • Protein: 20 g