This Roasted Veggie Breakfast Casserole is the marriage of a sheet pan dinner and a casserole. Veggies and breakfast sausage are baked together in the oven before they’re transformed into a one-and-done breakfast that can be enjoyed all week long!
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We all know the importance of eating a healthy breakfast each day. But still…it can be hard to muster the time and energy to make a nutritious meal each and every morning.
The smart solution? A BIG breakfast casserole like this one. Spend just 15 minutes of prep to pull it together, then get it into the oven while you start your day (or make it ahead the night before). With a dozen servings, you’ll have enough to get you and your family fed well into the week. Since this recipe freezes well, you can also stash some individually-wrapped squares in the freezer for busy mornings down the road.
Packed with bell peppers, red onions, eggplant, and asparagus, this breakfast dish is as delicious and colorful as it is nutritious. But it’s also super easy to riff on: it’s a great way to use up those leftover mushrooms, squishy tomatoes, nearly past-its-prime zucchini, or shredded cheese lingering in the fridge.
If you’re looking for more grab-and-go breakfast options, give our copycat Starbucks egg bites, balanced breakfast egg cups, and frozen breakfast sandwiches a try!
Why You’ll Love This Recipe
- 1 casserole = 12 servings
- Super flexible recipes allows you to use whatever veggies, breakfast meat, cheese, and other ingredients you have on hand
- Ideal for meal prep
Breakfast Casserole Recipe Ingredients
Here’s everything you’ll need to whip up this hearty breakfast casserole. Find ingredient notes (including substitutions and swaps) below.
For the vegetables:
- Bell Peppers – we call for 2 red bell peppers
- Onion – you’ll use 1 medium red onion
- Eggplant – add to that 1 medium eggplant
- Asparagus – you’ll also use 1 whole bunch of asparagus
- Olive Oil – drizzle the veggies with 1 tablespoon extra virgin olive oil
- Salt – 1/2 teaspoon sea salt seasons it all
- Pepper – 1/4 teaspoon pepper adds a little kick
- Sausage – you’ll also need 2 pounds of your favorite breakfast sausage
For the casserole:
- Eggs –you’ll use two full cartons of eggs for this generously-sized casserole!
- Salt – season the eggs with 1/2 teaspoon sea salt
- Black pepper – just 1/4 will do
- Bagel Spice Blend – 1 tablespoon adds bold flavor!
A full ingredient list with exact amounts can be found in the recipe card below.
Recipe Variations and Modifications
This flexible dish easily adapts to your choice of ingredient swaps and add-ins:
- Veggies – if you don’t have, or don’t like all the veggies we call for here, feel free to swap in whatever you’d prefer: mushrooms, zucchini, tomatoes, and sauteed greens would all taste delicious.
- Cheese – add some shredded cheddar, Parmesan, or mozzarella to the uncooked egg mixture, or to the top of the casserole for a browned, cheesy crust.
- Herbs – mix in some fresh chopped herbs like basil, parsley, or thyme.
How to Make Breakfast Casserole
Here’s how this easy egg dish comes together with just 15 minutes of prep time.
Step 1: Preheat the oven to 375 F. Place the chopped bell peppers, red onion, eggplant, and asparagus on one large, or two medium, sheet pans and drizzle with olive oil.
Step 2: Drop bite-sized pieces of the breakfast sausage on top of the vegetables and bake for 45 minutes, until caramelized.
Step 3: In a large bowl, whisk together eggs, salt, and pepper.
Step 4: Add vegetables and sausage to a deep 9×13 inch baking dish. Pour the eggs over the vegetables, then sprinkle on bagel spice blend.
Step 5: Bake the casserole for 30-35 minutes or until the center is firm (give it a shake and if it jiggles, it needs more time).
Let the casserole cool for 5-10 minutes, then cut and serve!
Recipe Tips
- Roasting the veggies – Don’t be tempted to skip the step of roasting the veggies before adding them to the egg mixture. Since vegetables naturally contain so much water, this step concentrates their flavors and prevents the casserole from being too watery.
- Same-size your veg – To ensure that your veggies cook at the same rate, cut everything into 1-inch pieces.
- Sausage – With this oven method, you don’t need to cook the breakfast sausage separately on a stovetop. Just add it raw in clumps over the veggies before cooking, and everything will be perfectly browned.
How to Serve
Cut the casserole into 12 squares (less servings if you’d prefer bigger portions). Eat the squares while hot, or at room temperature.
How to Store and Reheat
This dish keeps/reheats REALLY well! Just use the microwave until heated through.
For leftovers, wrap individual servings in parchment paper and refrigerate for up to 5 days.
Frequently Asked Questions
Like this recipe, most breakfast casseroles are a mix of eggs with vegetables and/or meat, cheese, and seasonings.
If your egg dish comes out watery, vegetables are usually the culprit. Since veggies are mostly comprised of water, they leach moisture into the egg mixture as the casserole cooks. That’s why, in this recipe, we roast the veg before it gets added into the eggs, which evaporates some of that liquid.
More Favorite Breakfast Recipes
If you tried this recipe for Roasted Veggie Breakfast Casserole, or any other recipe on the Fed & Fit website, please leave a 🌟 star rating and let us know how it went in the 📝 comments below!
Roasted Veggie Breakfast Casserole
Ingredients
For the Vegetables:
- 2 red bell peppers, cut into 1-inch pieces
- 1 medium red onion, cut into 1-inch pieces
- 1 medium eggplant, cut into 1-inch pieces
- 1 bunch asparagus, thick stems discarded, cut into 1-inch pieces
- 1 tablespoon extra virgin olive oil
- 1/2 teaspoon sea salt
- 1/4 teaspoon pepper
- 2 pounds bulk breakfast sausage, without casings
For the Casserole:
- 24 large eggs
- 1/2 teaspoon sea salt
- 1/4 teaspoon black pepper
- 1 tablespoon bagel spice blend
Instructions
- Preheat the oven to 375 F.
- Place the chopped bell peppers, red onion, eggplant, and asparagus on one large, or two medium, sheet pans and drizzle with olive oil. Drop bite-sized pieces of the breakfast sausage on top of the vegetables and bake for 45 minutes, until caramelized.
- In a large bowl, whisk together eggs, salt, and pepper.
- Add vegetables and sausage to a deep 9×13 inch baking dish. Pour the eggs over the vegetables, then sprinkle on bagel spice blend.
- Bake the casserole for 30-35 minutes or until the center is firm (give it a shake and if it jiggles, it needs more time).
- Let the casserole cool for 5-10 minutes, then cut and serve!
Nutrition
Delicious! Made with bacon instead and it was great.
We’re so glad you enjoyed this recipe, C!
I try to stay away from eggs. Is there an egg substitute?
Since the eggs make up the bulk of this breakfast casserole, subbing them would be really tricky. Check out some of our favorite egg-free breakfasts, though: Sheet Pan Sweet Potato Hash, Chorizo Potato Breakfast Meatballs, DIY Egg Free Breakfast. Enjoy!
This is my go to recipe when I have a bunch of vegetables that need to be used asap. Easy and delicious way to incorporate all the veggies.
Agreed!! Thanks so much for sharing this with us, Sarah!
Excellent recipe! I used zucchini, summer squash and beets from the garden… sooooo yummy! Also, I didn’t have a deep baking dish, so I split it into two baking dishes and cut one up into single portions for the freezer for later :).
How smart! What great subs, and how smart to freeze in single portions! Thank you for taking the time to share with us. We really appreciate it! -Team FF
Hi! I’m making this as a freezer meal in prep for postpartum. I have read through your freezer prep page which led me to this recipe! How long should this last in the freezer? I plan to cut into individual squares and wrap in parchment paper like you suggested. Thanks for helping me stay fed once this baby comes!
Hi Victoria! That’s a great way to store your casserole! This recipe should last in the freezer for 3-6 months. So glad it will provide you nourishment in your postpartum period.
Hi! I’m making this as a freezer meal in prep for postpartum. I have read through your freezer prep page which led me to this recipe! How long should this last in the freezer? I plan to cut into individual squares and wrap in parchment paper like you suggested. Thanks for helping me stay fed once this baby comes!
Can I substitute mushrooms to use instead of eggplant? Can I add winter squash or substitute it for something else?
Absolutely! You can use whatever veggies you like best here.
So stupid question, the only 9×13 pan I have is just a regular pyrex 9×13 glass casserole dish…is that deep enough? 2 dozen eggs and 2 pounds of meat sounds like it may not fit…I also have a a regular depth 11×15 glass casserole dish, would that work better? I’m just picturing a TON of egg mixture 🙂
Thanks Cassy, love your recipes 🙂
I’d go with the 11×15 just to be safe, this one was definitely on the deeper side!