Very Veggie Spring Green Breakfast Casserole

This vegetarian breakfast casserole is my go-to dish to serve at a family brunch. The best part? The layer of roasted sweet potatoes on the bottom!

Vegetarian Breakfast Casserole

I love a good frittata. Frittatas are my go-to choice for brunch if Jack and I are hosting a couple of people. Now that we’re living around more family here in Chicago, I’ve changed things up – this vegetarian breakfast casserole is basically a frittata in casserole form. Why? Well with a casserole, you get a lot more portions with no more work. It’s perfect if you’re hosting a Mother’s Day get-together with your family this weekend! 

Healthy breakfast casserole ingredients Vegetarian breakfast casserole ingredients on baking sheets

Speaking of moms, I borrowed (er…took?) this vegetarian breakfast casserole recipe from my mom. She first started making it around the time of my sister’s baby shower last spring and it has become her go-to brunch recipe ever since. My favorite part is the hearty layer of roasted sweet potatoes on the bottom. Since the sweet potatoes naturally sink to the bottom of the egg mixture, they create a beautiful and delicious base to this egg dish. My mom makes her recipe with bell peppers and zucchini, but I swapped in asparagus and peas to celebrate spring. Along with the mushrooms and scallions, this healthy breakfast casserole is positively packed with vegetables.

Whisking eggs for breakfast casserole in a bowl Vegetarian breakfast casserole

Since I don’t drink regular milk, I reached for Almond Breeze to whisk into the eggs, but then I thought – ah ha – I’ll switch things up by using their Almond Cashew blend instead. It’s made with a creamy mix of almond milk and cashew milk, so it makes these eggs nice and fluffy, but decadent at the same time. If you skip the feta, this healthy breakfast casserole recipe is entirely dairy-free, but I really love feta cheese’s tanginess in this one, so I don’t recommend leaving it out :).

Just look at that sweet potato layer that I was talking about – yum!

Healthy breakfast casserole

Thanks, mom, for the recipe!

Very Veggie Spring Green Breakfast Casserole
Prep time
Cook time
Total time
Recipe type: Breakfast, brunch
Serves: 10-12
  • 2 sweet potatoes, cubed
  • 10 to 12 ounces mixed mushrooms, (cremini mushrooms, quartered)
  • 1 bunch asparagus, tender parts, chopped
  • Extra-virgin olive oil, for drizzling
  • 12 large eggs
  • ½ cup Almond Breeze Cashew Blend Unsweetened Original
  • 1 garlic clove, minced
  • ½ to 1 teaspoon sea salt*
  • ½ teaspoon black pepper
  • 4 ounces crumbled feta cheese
  • 1 bunch scallions, chopped
  • 1 cup frozen peas, thawed
  • Microgreens, optional, for garnish
  1. Preheat the oven to 400°F and line 2 baking sheets with parchment paper. On one baking sheet spread the sweet potatoes, on the other baking sheet spread the mushrooms and asparagus. Drizzle with olive oil and sprinkle with pinches of salt and pepper and toss to coat. Roast the sweet potatoes for 30 minutes. Place the baking sheet with the mushrooms and asparagus in the oven to roast during the final 10 minutes.
  2. In a medium bowl, whisk together the eggs, milk, garlic, salt, and black pepper.
  3. Reduce the oven temperature to 350°F. Lightly spray a 9x13-inch** baking dish with nonstick spray. Place all the sweet potatoes evenly in the bottom of the baking dish. Add half of the vegetables from the second baking sheet and spread out evenly. Sprinkle with the feta cheese, scallions, and peas.
  4. Pour the egg mixture evenly over the vegetables. Add the remaining mushrooms and asparagus.
  5. Bake for 40 to 45 minutes or until the eggs are set and the edges are lightly golden brown. Let the casserole sit for 10 minutes before slicing.
  6. Garnish slices with microgreens and season with additional salt and pepper, if desired.
* Use ½ teaspoon salt if using the feta cheese; use 1 teaspoon salt if omitting the feta cheese.
** Although the pan in the photo is a bit smaller than a 9x13, the recipe fits into a standard 9x13 pan. If you use a smaller pan, you'll need to use multiple pans.



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Rate this recipe (after making it):  

  1. Liese

    That looks very pretty and the veg combo sounds great…I’m going to veganize it with a thin bechamel sauce, tofu based “feta” or maybe slices of Follow your heart smoked gouda and a good layer of sliced sweet potatoes to soak up the liquid.

    • I just loved the recipe and I am gonna try to make it in the upcoming weekend.

  2. sabrina from

    you already got my attention with sweet potatoes, but also like the almond cashew milk, didn’t even know it existed as a product, just something you’d have to make, so love that too since I don’t usually drink milk either, love all of the rest too, very nice recipe, thank you!

    • Jeanine Donofrio

      it’s really good and a bit creamier than regular almond milk. I find it at Target, just fyi.

  3. Brittany Audra @ Audra's Appetite

    I completely agree with you!! I love making frittatas for guests when they come to visit for a healthy yet delicious brunch!

  4. Aastha

    this looks delightful! question- if using regular milk, since I always have that in my fridge, should i use the same amount?

    • Jeanine Donofrio

      yep – the same!

  5. Eva from

    Jummie! Ziet er heerlijk uit! 🙂

  6. Marsha Berberich

    If using the bell peppers and green beans as in your moms original recipe, how much of each and which color of peppers does she use? Thanks so much!

    • Jeanine Donofrio

      She uses 1 green bell pepper and 1 red bell pepper (both diced), and 2 carrots sliced into thin coins… skipping both the asparagus and peas. Hope that helps!

  7. Marsha Berberich

    Sorry, in first post I meant to say zuchinni, not green beans!

  8. Gaby Dalkin

    This looks like a brunch must-have!

  9. 1) Your pictures are absolutely gorgeous! 2) This looks delicious and not too time consuming to make. I can’t wait to try!

  10. Kimberly Baxter

    Made this for breakfast yesterday. So good! Thanks for the recipe.

  11. Meg

    How long would this keep in the fridge?

    • Jeanine Donofrio

      I keep it in the fridge for 2-3 days after making it. It’s best just out of the oven – if you’re serving it to guests, I’d make it on the same day. The leftovers are great for quick weekday breakfasts.

      • Meg

        Beautiful! I was planning to make a half recipe for a quick breakfast option for me and my partner, so lovely to know that it keeps well! Thank you so much for all your wonderful recipes. <3

  12. Roberta

    I made the recipe and love the nutrient rich ingredients and it looked so pretty, too!
    Although you reply above that it is best served out of the oven, can you tell me if you can prepare it, refrigerate it uncooked overnight and then cook it the next morning? I would like to serve it to guests but would love a partial make ahead option so you get the best of both worlds, advance prep but just baked when serving.

    Second, I enjoy some spice and wonder if you would serve it with sriracha sauce? Any ideas???

    • Jeanine Donofrio

      Hi Roberta,
      Apologies for my slow reply – yes, my mom makes it the night before, keeps it in the fridge and then bakes it the next day to serve to guests.

      I love hot sauce on eggs – you could also add a diced jalapeño to the mix.

      Hope that helps!

        • Roberta

          Oops. I better be sure I am clear. When you write she makes it the night before, you mean she prepares it (up until baking instructions) and then bakes the next day. I know you can bake and reheat the next day but that wasn’t what I was asking. So, to clarify, the question is can you prepare it up to the point of baking, refrigerate it, and bake the next day? Extra baking time needed since it will be cold??? Thanks for clarifying.

          • Jeanine Donofrio

            yes she prepares it and puts it in the fridge un-baked. She bakes it about 5-10 minutes longer. I’d just press the center to make sure the eggs are set before you take it out.

  13. Roberta

    Perfect! Thanks, again!!!

  14. Lara

    could you tell me what casserole dish you use? I’m in the market for a new one 🙂

  15. E

    Are you using different types of mushrooms on this recipe? From the photos, looks like the dish has both Cremini and Shumeji mushrooms. Would love to know if that’s the case. Will try to make this recipe next weekend.

    • Jeanine Donofrio

      Yep, I used both – as long as the total mushroom amount is 10 to 12 ounces you can mix!

  16. Haley

    I love that it has sweet potatoes in it.

  17. Megan

    This is the perfect breakfast for a brunch or even a Christmas party.

A food blog with fresh, zesty recipes.
Photograph of Jeanine Donofrio and Jack Mathews in their kitchen

Hello, we're Jeanine and Jack.

We love to eat, travel, cook, and eat some more! We create & photograph vegetarian recipes from our home in Chicago, while our shiba pups eat the kale stems that fall on the kitchen floor.