Rainbow Veggie Breakfast Casserole
This Vegetarian Breakfast Casserole with egg is LOADED up with all the colorful mixed veggies: sweet potatoes, broccoli, bell peppers, and more! It’s a great option for breakfast meal prep—leftovers are quick and easy to reheat. Unlike a lot of breakfast casseroles, this recipe doesn’t use hash browns!

Breakfast is supposed to be the most important meal of the day, right? Well, I personally think all the meals are equally important (I couldn’t possibly play favorites), but I do believe that starting out the morning with a veggie-loaded breakfast recipe can really set the tone for an overall great day.
Personally, I have found that a savory breakfast full of protein + veggies is the magical way to start the day (Try my Broccoli and Egg Breakfast Bake). I started the day feeling fueled, satisfied, and on a veggie-loaded foot.
This Vegetarian Breakfast Casserole is one of my favorite savory veggie packed breakfasts to make ahead of time. It’s loaded with colorful veggies (sweet potatoes, broccoli, bell peppers, tomatoes) and protein from eggs. The addition of pesto to this veggie breakfast casserole brings it next level in the flavor department. Since this recipe makes 10 servings, it is great to make for a crowd. Or, I love to make it during my weekly meal prep, store it in the fridge, and reheat a slice each morning in the oven or air-fryer. It is naturally gluten free along with being vegetarian, but you can make it dairy-free with a few small modifications.
Suggested adaptations
Use different vegetables. There are so many vegetables that would work well in this Vegetable Breakfast Casserole. You can use zucchini, cauliflower, greens like spinach or kale, peas, etc. Frozen vegetable will also work well, just make sure whatever vegetable you use in this recipe is mostly cooked through before you add the egg mixture on top.
Don’t like or have sweet potato? Regular potato varieties, such as Yukon Gold, would work well in this recipe, too.
Add cheese! Stir in about a cup of shredded mozzarella or cheddar or diced fresh mozzarella to the egg mixture to give the dish lots of extra yummy flavor.
Make it dairy-free. Be sure to use or make a dairy-free pesto (Trader Joe’s carries a good one!) and use an unsweetened, unflavored dairy-free milk.
Vegetarian not needed? Adding some cooked bacon or cooked breakfast sausage to this breakfast casserole would add wonderful flavor!
Want to find out the BEST way to cut bell peppers? Head over to my How To Cut a Bell Pepper…to minimize waste! post!
How to store and reheat this breakfast casserole
This veggie breakfast casserole is great to make ahead and keep in the fridge for a veggie-packed breakfast or quick meal any time of day. It will keep, well covered, in the refrigerator for 4 to 5 days.
I like to just cover the whole baking dish with foil for easy storage and then pop it into an oven at 350℉ to warm up for about 15 minutes. I keep foil on to prevent extra browning of the eggs.
If you prefer to reheat by the slice, you can use a toaster oven or pop a piece into a microwave to warm up on half power for about 30 seconds.
Other veggie-loaded breakfast recipes you will love
- Healthy Apple Carrot Pancakes
- Breakfast Pumpkin Soufflé
- Healthy Zucchini Bread
- Healthy Veggie-Loaded Egg Cups
- Veggie-Loaded Breakfast Cookie Recipe
- Sweet Potato Peanut Butter Muffins
- Mini Butternut Squash Blueberry Muffins
- Healthy Carrot Pumpkin Muffins
- Blueberry Cauliflower Oatmeal
Did you try this Vegetarian Breakfast Casserole and now you’re hungry for more?
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Rainbow Veggie Breakfast Casserole
Ingredients
- 3 teaspoons olive oil or avocado oil, divided
- 1 large sweet potato, washed and cut into ½-inch dice
- 1 teaspoon salt, divided and to taste
- black pepper, to taste
- 2 cups small broccoli florets
- 1 bell pepper, cut into ½-inch dice
- 10 large eggs
- ⅓ cup milk of choice
- ¼ cup pesto , store-bought or homemade pesto, dairy-free if desired
- 4 small tomatoes, such as Roma or on-the-vine
- ¼ cup snipped chives or sliced green onions
Instructions
- Preheat oven to 425℉. Grease a large baking dish (9-by-13 inch) with a teaspoon of oil (or use oil spray if you prefer).
- Place diced sweet potatoes in the baking dish. Drizzle with a teaspoon of oil and sprinkle with a pinch of salt and a few grinds of black pepper. Toss to coat, then spread into an even layer. Roast until the potatoes start to soften and brown, about 15 minutes.
- Toss the broccoli and peppers with the remaining teaspoon of oil and season with salt and pepper. Scatter the broccoli and peppers over the partially cooked sweet potatoes, then continue to roast. Cook until the broccoli tops begin to brown, about 10 minutes.
- Meanwhile, in a large bowl, whisk together the eggs, milk, and pesto. Season with a pinch of salt and a few grinds of black pepper. Cut tomatoes crosswise into 4 to 5 slices and set aside.
- Once vegetables are browned, remove the pan from the oven. Reduce the oven temperature to 350℉.
- Whisk the egg mixture again to make sure everything is well combined then pour it over the vegetables. Place sliced tomatoes over the top of pan in rows, then scatter with half of the chives or green onions.
- Bake until cooked through and the center of the casserole is firm, 20 to 25 minutes.
- Allow to cool for 5 to 10 minutes, sprinkle with remaining chives/green onions, then slice into squares. Serve warm or at room temperature. Store leftovers in fridge for up to 4 days.
Looks great! Do you think it would do well to be assembled and refrigerated before baking, say the night before?
I would say you could roast the veggies the night before but I would add the eggs right before baking!
I love the broccoli peaking out! I am wondering the same as Kelli – it seems like it would fare well in the fridge for a quick pop in the oven in the morning.
Love all those veggies! What a great start to the day – my girls would totally eat this right up! I love that most of this can be done the night before too!
This is exactly the health kick I need in the mornings… especially during the holiday season! Looks awesome!
This looks delicious! LOVE how many veggies you packed into this! Such a great way to start the day!
I could not agree more that you need a healthy and hearty breakfast to start your day out…makes all the difference in the world! Can’t wait to try this recipe!
Worthy of being packed up for both breakfast and lunch on a busy day! This looks fantastic – I love that the broccoli has a chance to crisp up a bit while baking too.
Love this breakfast casserole recipe ! Looks colorful, delicious, and nutritious !
broccoli and eggs are my favorite!! looks divine <3
I need to eat more vegetables for breakfast! This is perfect!
Looks like a tasty way to get in more veggies. ~ stacey
I love all the veggies in this- an awesome way to start the day! I always make a big egg dish like this on Sunday and eat it all week. This one looks so delicious!
Love the gorgeous light illuminating this… Really evokes the morning… 😀
Always looking for a great breakfast casserole to switch up my weekly routine 🙂 Looks amazing!!
What a great start to the day, and I’d probably make a huge batch to take leftovers for lunch because this looks right up my alley! 🙂
I absolutely love casseroles and there just aren’t enough of them (yet) on Paleo! But this looks perfect for those busy mornings when we are rushing to get everyone out of the house on time!
What a great casserole you have here! I must admit, I was giggling to myself when you motioned not being able to turn on the oven. That is exactly how I feel when I get up in the morning, can’t wait to try this one! ^5 sista
This looks great! So many delicious veggies!
Wow! This one is definitely going on my “to-make” list. I think this is going to make many families’ holiday just a little brighter. Thanks for sharing and happy holidays!
Is that really just 1/2 of a sweet potato or is that a typo?
Really just 1/2 a sweet potato. Most sweet potatoes tend to be pretty large, so a little goes a long way. But if your sweet potato is on the small side, using all of it would be fine.
I made this for breakfast this week and honestly I found it to be pretty dry and bland. I ended up adding bacon midweek and that helped give it some flavor. Honestly though, I think this recipe has potential but needs some further exploration.
Thank you for your feedback, Amber! There are so many ways to adapt this recipe to fit your personal tastes! Bacon sounds like a great addition to add a richer flavor! I love to add avocado on top of mine and my husband slathers his in hot sauce!
Hello! Looks delicious, wondering on about how many servings for this recipe?!
The Rainbow Veggie Breakfast Casserole is delicious! My 16 year old likes it, YIPPEE!!! Thank you for giving us yummy recipes!!!
Yay! Such a win!