Easy Gluten-Free Breakfast Casserole | Olivia's Kitchen (2024)

This easy breakfast casserole is perfect for weekend mornings, holiday brunches, or weekly meal prep. It features sausage, diced veggies, and hashbrowns, and encourages using what you have to create a custom casserole! This gluten-free and easily dairy-free breakfast casserole can also be made ahead of time for quick prep.

This Gluten-Free Breakfast Casserole is the perfect start to your day! Whether it's brunch, Christmas morning, or time for your weekly meal prep, this recipe is sure to hit the spot. The whole family will enjoy!

It's essentially a frittata or a crustless quiche, baked in a casserole dish and loaded with fillings (but no bread!). There's no shortage of flavor in this one. My recipe is filled with hash browns, sausage, onion, bell peppers, spinach, and cheese. This recipe is easily customized to your dietary preferences. Make it vegetarian, dairy-free—you name it!

Best part is that this casserole can be prepared in 30 minutes the night before you want to enjoy it. In the morning all you have to do is bake! It's also very freezer friendly so you can enjoy slices later when you need them.

Have I sold you yet? I'm already craving one. Keep reading to learn how you can make your own gluten-free breakfast casserole.

Why You'll Love This Recipe

• Delicious flavor!
• Get your protein, fat, carbs, and veggies. All in one delicious bake.
• Make ahead and bake in the morning. Just 30 minutes of prep the night before to save you stress in the morning.
• An impressive brunch dish.
• Easily customizable. Customize the fillings based on your tastes!
• Great for meal prep.
• Freezes well for later.See below for storage and freezing instructions. Breakfast casserole slices are great to keep on hand for those mornings when you need a quick bite.

What is a Breakfast Casserole?

Breakfast casserole is an American dish that is very similar to an Italian frittata or crustless French quiche. It may also be known as a gluten-free egg casserole. Essentially it is baked eggs with several mix-ins, fillings, and/or toppings eaten in slices for breakfast or brunch. This version is baked in a 9x13" casserole dish which makes it super easy.

The hash browns and sausage are certainly an American twist, but this recipe is easily customized to suit your preferences and dietary restrictions. This recipe is gluten-free and nut-free, and easily made vegetarian or dairy-free.

Ingredient Notes

Here is everything you'll need to make this delicious breakfast casserole:

• Italian pork sausage: Remove the casings so you're left with the ground sausage meat. Use hot or mild depending on your preference.
• Onion & bell pepper: We will cook them down slightly first to give flavor and softness.
• Frozen hash browns: Ensure yours are gluten-free! All I could find are the patties, but you could also use the small cubed hash browns, or shredded hash browns.
• Chopped spinach: I like to wilt fresh spinach but you could use frozen. Ensure you thaw and drain it well to avoid adding excess moisture.
• Eggs: Yes, there's a lot of eggs!
• Milk & shredded cheese:I use lactose-free 2% milk and old cheddar cheese. Use dairy-free if preferred.
• Spices: Don't skimp on the salt—it amplifies all the flavors in this casserole. Chili flakes are optional if you like a little heat.
• Toppings: I like to top my baked breakfast casserole with chopped green onions and hot sauce. Chives or BBQ sauce would be great options too!

Dairy-Free Breakfast Casserole

Make this a dairy-free breakfast casserole by using your favorite dairy-free milk and cheese. I recommend a neutral milk like cashew or soy, and a nice cheese that melts, like Violife. Add a tablespoon of nutritional yeast and a pinch of dry mustard to the egg mixture to boost the cheesy flavor.

Vegetarian Breakfast Casserole

Omit the sausage and bulk up the veggies for a vegetarian breakfast casserole. Sauté all your veggies in a little olive oil for 4-5 minutes and drain water if necessary prior to assembling the casserole so any excess moisture can be removed. Here are some of my favorite veggies to add:

• Onion
• Bell peppers
• Mushrooms
• Broccoli
• Zucchini
• Asparagus
• Chopped spinach
• Chopped kale
• Olives

Customizations

There are many ways to change up this breakfast bake depending on your dietary preferences and ingredients you have on hand. Here are some suggestions:

• Change the meat: Use ground beef, ground pork, breakfast sausage, ham, bacon, etc. About 1 lb of anything you have on hand.
• Change the veggies: Pick your favorites! See the vegetarian list above for some suggestions.
• No hashbrown patties? Use 2 cups of the little hash brown cubes or shredded hashbrowns. Still fry them in the skillet until golden before adding to the casserole.
• Swap the cheese: I like to use shredded cheddar cheese, but you could absolutely use mozzarella cheese, marble, goat cheese, feta, parmesan, etc. Measure cheese with your heart. ❤️
• No 9x13" pan? Try a cast iron large skillet: If you don't have a 9x13" baking dish, a 12" cast iron skillet will give you a very similar capacity. Bonus is you could sauté, assemble, and bake all in one pan!

Step-by-Step Instructions

Be sure to read the recipe card below for the full ingredient list and instructions for how to make this gluten-free breakfast casserole.

(Prep) Preheat the oven to 375ºF and grease a 9x13" casserole dish.

(1) In a large pan on the stove over medium heat, cook the ground sausage until brown, about 7-8 minutes. Use a spatula to break apart large chunks. Remove the meat to a large bowl, leaving the grease in the pan.

(2) Place the hashbrown patties in the pan and cook in the sausage fat. You may have to do this in 2 batches. Cook for about 7-8 minutes. Don't worry if the patties fall apart. In fact, you'll want to break them up with a spatula. Once golden, remove to a new bowl and set aside.

Add a drizzle of olive oil to the pan if it is dry. Sauté the onion and bell pepper for 4-5 minutes until soft. Remove to the sausage bowl.

Add the spinach to the pan and stir until wilted. Remove to the sausage bowl and stir everything together. Turn off the stove.

(3) In a large mixing bowl, whisk together the eggs, milk, cheese, and spices. You can do this while the previous steps are cooking.

(4) In the greased casserole dish, spread the hashbrowns in a layer covering the bottom.

(5) Then top with the sausage and veggie mixture, spreading into an even layer.

(6) Pour the egg mixture around the dish, then give it a little shake so the eggs settle evenly. Top with more shredded cheese if desired.

(7) Bake at 375ºF for about 40 minutes. Use a temperature probe to check that the centre has reached 160ºF. Broil for 1-2 minutes to melt the cheese more if desired.

Allow the casserole to cool for 10-15 minutes before cutting and serving, it will be very hot. Slice into 12 pieces and enjoy topped with green onions and hot sauce!

How to Serve

There are so many ways to enjoy a breakfast casserole. Here are some of my favorites:

• Bring to brunch! If you have a brunch potluck or want to impress your guests, make them this casserole.
• Prepare on Christmas Eve to bake on Christmas Morning! Prep ahead means more time to enjoy.
• Make for breakfast for the week. Bake the casserole on Sunday, then slice and portion enough in the fridge for a quick breakfast for the next 3 days.
• Stock the freezer. Prepare and bake the casserole, allow to cool completely, then slice and freeze in individual portions. Pull them out and reheat whenever you need! See freezer instructions below.

Here are some more easy breakfasts to serve with this gluten-free breakfast casserole: Gluten-Free Cheese Scones, Gluten-Free Pumpkin Spice Scones, Gluten-Free Banana Chocolate Chip Muffins, Homemade Gluten-Free English Muffins, Homemade Gluten-Free Bagels.

Make Ahead

Prepare the casserole through the end of step 6 above. Cover the dish with foil and refrigerate overnight. In the morning, preheat the oven, uncover, and bake.

Storage & Freezing

Storage:Allow leftover breakfast casserole to cool, then place slices in an airtight container and refrigerate for up to 3 days. Reheat in the oven at 375ºF for about 10 minutes or in the microwave for 2 minutes.

Freezing:Place cooled slices in an airtight container and freeze for up to 2 months. When ready to eat, remove desired portions and microwave for 3 minutes, or bake in the oven at 375ºF for 10-15 minutes.

Expert Tips

Here are some of my top tips and tricks for a delicious breakfast casserole:

• Customize the fillings to your liking! Make it vegetarian, dairy-free, meat lovers, etc!
• Sauté all meat and veggies before assembling the casserole. This will remove excess moisture.
• Shake the casserole dish to distribute egg mixture evenly.
• If preparing ahead, bake no later than the next morning. Food safety!
• Best served immediately, or freeze.If you don't eat the whole casserole, store slices in the fridge for a maximum of 3 days. Freeze the rest for up to 2 months. Thaw in the microwave or oven at 375ºF until warm throughout.

Frequently Asked Questions

This gluten-free breakfast casserole is a delicious savory dish perfect for a weekend brunch or your weekly meal prep. It is easily made ahead of time and can also be frozen and enjoyed at your leisure. This recipe is super customizable to be dairy-free or vegetarian too! Hope you enjoy and leave a ⭐️⭐️⭐️⭐️⭐️ review below!

More Gluten-Free Breakfast Recipes

• Homemade Gluten-Free Bagels
• Cheese Scones
• Blackberry Strawberry Banana Smoothie
• Vegan Dirty Chai Scones
• Mango Hurricane Smoothie
• Pumpkin Spice Scones
• Homemade Gluten-Free English Muffins
• Lemon Blueberry Scones
• Pumpkin Banana Muffins
• Banana Chocolate Chip Muffins

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Have you made this gluten-free breakfast casserole? I'd very much appreciate it if you leave a 5-star rating ⭐️⭐️⭐️⭐️⭐️ below, and tag me on instagram @fromoliviaskitchen!

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