Easy Vegetarian Breakfast Casserole

The vegetarian breakfast casserole is loaded with fluffy eggs, peppers and mushrooms, vegetarian sausage, hash browns and cheddar cheese. You can enjoy a slice of this customizable and easy to make breakfast recipe in under an hour!

Whether you want to feed a family or enjoy a week of meal prep, this casserole is sure to start your day off right.

This recipe has 8 servings of fluffy egg, hashbrowns, cheese, and veggie sausage and can be easily made ahead!

You can easily customize the casserole to meet your preferences. Just choose your favorite veggies, favorite cheese, and favorite veggie sausage (or just leave it out entirely)!

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When I think about the Christmas traditions I enjoyed growing up, I think about food. And while most people may look forward to a big Christmas dinner, I'm all about that classic Christmas breakfast: egg casserole and fresh homemade cinnamon rolls.

I shared my cinnamon roll recipe last week, so now it's time for the healthier component of my favorite Christmas tradition: vegetarian breakfast casserole. 

Despite the fact that egg casserole is an annual tradition in my house, we've rarely used the same recipe twice. My mom finds a new recipe almost every year, changing a few ingredients here and there to fit our family's preferences.

When I became a vegetarian in college, I threw my mom's casserole for a bit of a loop. You mean... breakfast casserole without sausage? Yep. After a few years of experimenting with vegetarian breakfast bakes, I've found a go-to recipe. No more changing the recipe every year in search of the perfect dish!

Since first making this recipe, I've also shared a sweet potato collard green egg bake and mushroom goat cheese frittata that you'll want to check out.

Main ingredients

There are five main components to this recipe:

• Hashbrowns. Thawed frozen hashbrowns are used in this recipe. For extra texture, I like to brown them slightly before adding them to the casserole dish.
• Vegetarian sausage: Such as Morningstar brand. This step isn't necessary, but it adds that classic breakfast bake feel. And it makes the meat-eaters in my family a little happier.
• Bell peppers and mushrooms: Feel free to mix in whichever veggies you prefer; these are just my classic breakfast veggie choices.
• Shredded cheddar: Cheddar is the traditional choice, but mozzarella or Italian blend are also good options.
• Eggs mixed with milk. I usually use 2% milk, but non-dairy milks like soy milk also work well. 

Step by step recipe instructions

I recommend sautéing the vegetables until softened instead of adding them straight to the unbaked casserole. This deepens their flavor and makes the casserole even better! If you're short on time you can skip this step and add raw vegetables directly to the other ingredients.

The only other prep you need to do is to whisk together eggs, milk, and seasonings like you're making scrambled eggs.

1. Start by layering a lightly oiled 9x13 inch casserole dish with the hashbrowns. Make sure they're already defrosted so that they don't defrost while baking and add extra liquid to the casserole. Season with a bit of salt and pepper.
2. Add the crumbled veggie sausage and veggies. I use sautéed mushrooms and bell peppers, but you can use any variety of diced veggies here.
3. Sprinkle the cheese on the veggies.
4. Pour on the whisked eggs. Place the casserole in the oven and bake for 35 minutes. Let rest for 5 minutes before slicing.

Can I make egg casserole ahead?

This recipe can be prepared up to 24 hours in advance.

To make ahead, assemble according to the recipe instructions. Cover with foil or other lid and refrigerate (I love these baking dishes because they come with reusable lids).

When ready to make, remove lid container and bake in the oven for 35-40 minutes at 350. It will require extra cooking time because the casserole is cold from the fridge. 

Have leftovers? Egg casserole will last covered in the fridge for 3-4 days and can be reheated for in the microwave in about a minute. 

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