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Broccoli, mushroom, egg and cheese breakfast casserole recipe {vegetarian, gluten-free}

Broccoli, mushroom, egg and cheese casserole, for breakfast or worknight dinner.

On any given Sunday morning, you can find me standing at the butcher block counter in my kitchen, all-important first cup of coffee within easy reach, eggs and shredded cheese and odds and ends of vegetables arrayed before me. Even without coffee -- even in my sleep -- I can preheat the oven and whip up a breakfast casserole in less than ten minutes. And half an hour later, when my household wakes up, something like this broccoli, mushroom, egg and cheese casserole will be there to greet them. I'm a huge fan of protein-centered breakfasts, and I also love egg and cheese casseroles for lunch or worknight dinners. Unlike souffles, egg casseroles aren't fussy, which is good to know if you're planning to cook while not quite fully awake.

Broccoli, mushroom, egg and cheese casserole (The Perfect Pantry).

Broccoli, mushroom, egg and cheese breakfast casserole

From the pantry, you'll need: eggs, shredded cheese, onion, thyme, cooking spray, kosher salt, fresh black pepper.

Serves 5-6.


1 medium onion, diced
2 cups roughly chopped broccoli florets
1/2 cup roughly chopped mushrooms (any variety; I like cremini)
8 large eggs
2 Tbsp nonfat milk
7 oz shredded cheese (I use fat-free mozzarella)
1 Tbsp dried thyme leaf, or 2 Tbsp fresh thyme leaves
1/4 tsp kosher salt
1/2 tsp fresh black pepper
Cooking spray


Preheat the oven to 375°F.

Place the onion, broccoli and mushrooms in a microwave-safe glass bowl (I use a 4-cup glass measuring cup). Add 1 tablespoon of water. Cover with plastic wrap, and be sure to leave a small vent hole. Microwave on high for 2 minutes. If the broccoli hasn't softened, cook on high for another minute. Uncover, drain off any liquid, and set aside.

Spray a casserole dish with cooking spray. Spread the vegetables in the dish, and allow them to cool slightly while you prepare the remaining ingredients.

In a large bowl, whisk the eggs until slightly frothy. Add the milk, and whisk to combine. With a rubber spatula, stir in the shredded cheese, thyme, salt and pepper.

Pour the egg mixture over the vegetables in the casserole dish. Draw the spatula through the mixture to bring some of the vegetables to the surface.

Bake, uncovered, for 35 minutes, until the eggs are puffy. Serve hot, warm or cold.

[Printer-friendly recipe.]

More breakfast treats:
Corn, green chile, egg and cheese casserole, from The Perfect Pantry
Kale, mushroom and caramelized onion breakfast casserole, from The Perfect Pantry
Crab, scallion and tomato quiche, from Cooking On the Side
Smoked salmon egg casserole with potatoes and dill, from Cookin' Canuck
Turkey egg breakfast casserole, from The Chic Life
Eggs Florentine casserole, from The Pioneer Woman Cooks

Broccoli, mushroom, egg and cheese breakfast casserole: bake in the oven and it's ready in under an hour. From The Perfect Pantry.

Disclosure: The Perfect Pantry earns a few pennies on purchases made through the Amazon.com links in this post. Thank you for supporting this site when you start your shopping here.


Honestly, Lydia, my first thought on reading this was that I could prep the veg the night before while fixing dinner. Then I realized it's the perfect supper meal on CSA pick up nights during broccoli season. We pick up between 4-6 pm, and usually I don't have anything planned for dinner because I don't know what will be in the box.
We get eggs in our farm share, so to be able to throw a fast casserole in the oven, then leisurely unpack the rest of the crate while it bakes, would be heavenly.


Okay, my favorite part of this is that you microwave the vegetables in a glass measuring cup. Why didn't I ever think of that? Often times I am loathe to drag out the frying pan to sauté vegetables, but this is such an easy alternative.

I love eggs as a vehicle for using up anything! I just made a frittata to use up a bag of spinach and threw lots of other yummy stuff! hooray for eggs!

Kirsten, great idea to prep the veggies ahead of time. Even without doing that, the casserole comes together in minutes.

TW, another plus to microwaving (other than the pure convenience) is that it doesn't add any oil to the casserole.

Carol, I'm the same way. I love egg and cheese casseroles and make them with so many combinations of things I find in my fridge.

We should have had this for breakfast today. I've had something frittata-ish on the brain with lots of veg. Cool idea to microwave the veg -- sounds delish.

This does sound terrific!

Kellypea, I'm all for any shortcuts that make it easier to cook first thing in the morning!

Cary, hope you try it.

Beautiful casserole with wonderful flavors and textures, Lydia! I often microwave onions, but not usually mushrooms or broccoli. I agree with T.W. that that's a terrific idea!


Shirley, it always makes me feel good to get some of my daily dose of green vegetables first thing in the morning. Hope you try this one.

I am so hungry this breakfast looks really delicious..thanks Lydia

Your breakfast casserole would make a lovely addition at a brunch buffet.

We love this kind of dish but for lunch or dinner! Not only is it healthy and delicious but you can change the vegetables and the cheese and personalize it - or use whatever is in the house. I love this!

Karen, it surely would.

Jamie, these types of casseroles are as much a worknight dinner favorite for us as they are a brunch standby. Once you master the method, the specific ingredients can be whatever you pull from the fridge. That's my favorite kind of cooking.

Hey Lydia, do you use a 7 x 11 or 9 x 13 casserole?

Jill, you can use either one, though a 9x13 will make a very thin casserole. I usually use ovals, but all different sizes, and sometimes a square 12x12 if that's what I grab first.

A perfect breakfast!

Kalyn, this is pretty much my perfect breakfast, too.

Can you use almond milk for this instead of dairy milk?

Andrea, I personally find the taste of almond milk to be very "almondy", and I wouldn't substitute it here. Soy milk, maybe. There is very little milk in the recipe, so you might do better to leave it out altogether.

I just prepared this quiche for breakfast today and is delicious. I add some red peppers and jalapenos to make it spicy

I have a brunch at work and some are vegetarians, I think this will work great, but maybe not enough to share with that many people. Do you think adding a small layer of hashbrowns would help it from being too thin in a 9x13?

Amy, you can definitely add potatoes. Egg casseroles are so flexible. Set them in a layer, or mix them right in with the broccoli.

How long will this keep in the fridge?

Charlene, 3-4 days, covered with plastic wrap or in a container with a tight lid.

I added 3/4 cup of grape tomatoes, cut in half , skipped the milk and did 10 eggs instead of 8. I increased cook time to 45 minutes on the highest rack & it was AMAZING, like an omelette in a dish!

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