This vegetarian breakfast casserole is the perfect healthy breakfast recipe to feed a crowd or to make-ahead for a quick breakfast during the week! Not only is this recipe vegetarian but it’s also high in protein and low carb friendly. So if you’re looking to eat more vegetables and protein, then this is a great recipe to add to your meal plan!
I have a few different egg casseroles (or bakes) on my blog but I wanted to put together a vegetarian breakfast casserole because I had some leftover vegetables in my refrigerator that needed to be used up. Plus, I’m always looking for more ways to pump up my daily vegetable consumption!
This recipe is actually super versatile. You can use any vegetables you have on hand which is great if you have a bunch of veggies you need to use before they go bad.
Frequently Asked Questions About Vegetarian Egg Casserole
Before I jump into this recipe, I wanted to answer a few questions I received from some of my readers about this delicious vegetable breakfast casserole.
Can I Replace Half The Eggs With Egg Whites?
If you want to reduce the fat in this recipe, then you can use half egg whites and half whole eggs.
I’ve made many egg casseroles replacing half the eggs with egg whites and it’s still just as tasty! The only thing is you might want to add a couple more egg whites to make up for the yolks not being used.
Can I Use Frozen Vegetables?
Yup! Just make sure that the vegetables are cooked completely and the liquid is squeezed out before stirring it into the egg bake.
Can I Make This Dairy-Free?
Yes, of course. You can substitute unsweetened coconut or almond milk for the dairy milk. You can also leave the cheese out or use a dairy-free cheese.
How Can I Add More Fiber and Protein?
A great way to bulk up this vegetarian egg casserole is to add some cooked quinoa. I’ll add around 2 cups of quinoa to an egg bake when I use it. It may sound odd but I promise it’s really good!
Can I Add Meat To This Vegetarian Egg Casserole?
Yep! I like having vegetarian options but if you want to add some meat to this recipe, then go for it! Some options are:
- Cooked chicken sausage. I like (and recommend) the brand Al Fresco. I just cut this up into small pieces and then stir into the egg bake with the veggies.
- Breakfast sausage. This will need to be cooked ahead of time. So, cook it first and break into small pieces as it cooks. Then, stir in with the vegetables.
- Cooked crumbled bacon. You can purchase the precooked bacon or cook the bacon ahead of time and crumble it in. I’ll make about a 1/2 pound or more of bacon and just stir it in with the vegetables.
What Other Cheese Options Are Good?
My favorite cheese to use in a vegetarian breakfast casserole is feta. Everything is better with feta!
But, when I made this all 5 kids were here, a few of them don’t like feta. How is that even possible?
Anyways, I decided to use sharp cheddar cheese instead which was still tasty. You can really use any cheese you like!
Vegetarian Breakfast Casserole
To make this breakfast dish, these are the ingredients you will need:
- Large eggs
- 1% milk
- Sliced mushrooms
- Bell pepper (chopped)
- White onion (chopped)
- Frozen broccoli
- Taco cheese
- Garlic powder
- Onion powder
- Olive oil
Prep The Vegetables Beforehand
I highly recommend cooking the vegetables first prior to adding the egg bake. Vegetables tend to release a lot of liquid so adding them raw could release too much liquid into the egg mixture. Also, cooking the vegetables first gives you a chance to add a little more flavor.
I’ve cooked the vegetables a couple of different ways:
- My go-to method is to simply cook all the vegetables in a pan on the stovetop. This is super quick and easy! All I do is sauté the vegetables in some olive oil until everything is tender and cooked and season with salt and pepper.
- If I want more flavor I’ll roast the vegetables. This does take a little longer but it’s a great way to add another layer of flavor. All I do is mix the vegetables with a tablespoon or so of olive oil and then roast in the oven for about 30 minutes in a 400-degree oven.
Regardless of the method you choose, make sure to remove as much liquid as possible before adding them to the egg casserole. Too much liquid will result in a mushy egg bake!
How To Make Veggie Casserole For Breakfast
Even though this egg bake takes a couple of extra steps, it’s actually quite easy to put together!
While the oven is preheating to 350 degrees, spray a 9×13 baking dish with some cooking spray and set it aside for later.
Place all of the cooked veggies into the baking dish.
In a large mixing bowl, whisk the eggs, milk, garlic powder, onion powder, salt, and pepper until everything is combined together.
Pour the egg mixture over the vegetables and then give it a couple of gentle stirs to make sure everything is mixed well together.
Place the dish into the oven and bake for 40 – 45 minutes or until the center is set.
How To Make Breakfast Casseroles Ahead Of Time
Egg casseroles are one of my favorite breakfast recipes to make ahead of time. They are super easy to make!
After the breakfast casserole is done, then I let it cool down, slice it up and store in glass meal prep containers for the week. In the morning, I take out a slice and warm it up for 1-2 minutes in the microwave. It heats up perfectly!
Then, I either eat as is or enjoy it with a slice of whole-grain toast.
There are two other ways to make-ahead this vegetarian egg casserole:
- Cook the vegetables ahead of time. This way when you’re ready to put the egg bake together and all you need to do is whisk up the eggs, stir in the vegetables, and bake.
- Prep the entire dish the night before. In the morning, when you’re ready to cook, just continue with the cooking instructions. You might need to add a few more minutes to the cooking time because it’s going to be cold.
More Breakfast Recipes
If you loved this vegetarian breakfast casserole, check out some of my other breakfast recipes!
- Breakfast Sandwiches
- Banana Chocolate Chip Cookies
- Bacon and Cheddar Breakfast Burritos
- Greek Quinoa Breakfast Bowl
- Super Greens And Chicken Sausage Egg Bake
If you are looking for something light and healthy to eat for breakfast, try making this veggie egg bake to eat for the week! Share a picture and tag me on Instagram or Facebook if you decide to make this!
- 12 large eggs
- 2 tablespoons olive oil, divided
- 8 ounce package sliced mushrooms
- 1 bell pepper, chopped
- 1 medium white onion, chopped
- 1 cup frozen broccoli
- ½ cup 1% milk
- 1 teaspoon garlic powder
- 1 teaspoon onion powder
- 1 teaspoon salt
- 1 teaspoon pepper
- 1 cup shredded sharp cheddar cheese
- Preheat oven to 350 degrees.
- Spray in a 9 x 13 baking dish and set aside.
- In a medium sauté pan heat 1 tablespoon of olive oil over medium heat. Add the sliced mushrooms and cook until tender, about 5 minutes. Place the cooked mushrooms into the baking dish.
- Using the same pan, heat the last tablespoon of olive oil over medium heat. Add the onion and bell pepper and cook until onion is translucent and both vegetables are tender.
- While the onions and peppers are cooking heat the broccoli in the microwave until it's heated through. Then add the broccoli to the pan with the onions and peppers. Break up the broccoli into small pieces as it cooks completely.
- Place the rest of the vegetables into the baking dish.
- In a large mixing bowl (you can do this step while the vegetables are cooking) whisk the eggs, milk, garlic powder, onion powder, salt, and pepper.
- Pour the egg mixture over the vegetables and then give it a couple slow stirs.
- Place the dish into the oven and bake for 40 - 45 minutes or until the center is set.
- Serve warm.