This rich, tasty, and filling keto breakfast casserole is made with sausage, eggs, spinach, and cheese. It's wonderfully flavorful!
It's also incredibly easy to make, and you can bake it ahead of time and reheat it - the leftovers are excellent.
In addition to breakfast egg muffins, this keto breakfast casserole is one of my favorite breakfasts to make when I invite friends over for brunch. It's rich and flavorful, and I can make it in advance and reheat it.
Many casseroles are tasty but not pretty, but this one is gorgeous, which is another advantage. The cheese topping becomes golden as it bakes, and the spinach adds a nice color.
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Ingredients
You'll only need a few simple ingredients to make this casserole. The exact measurements are included in the recipe card below. Here's an overview of what you'll need:
- Eggs: I use large eggs in most of my recipes, this one included.
- Heavy cream: I like to add it to the egg mixture for extra creaminess.
- Seasonings: Kosher salt, black pepper, garlic powder, and red pepper flakes.
- Shredded cheese: I use sharp cheddar. But you can use any melty cheese. Provolone and gruyere are also very good in this recipe.
- Fresh pork sausage: I buy mine at Whole Foods. You can make your own by mixing fresh ground pork with spices, as I do when making sausage patties.
- Fresh spinach: I use whole baby spinach leaves in this recipe. I don't chop them.
Variations
- You can use any type of sausage you enjoy. Breakfast sausage has the traditional flavors that we associate with breakfast meat. But there's no reason not to use Italian sausage or spicy sausage.
- If you don't eat pork, you can use chicken sausage.
- You can replace the heavy cream with softened cream cheese or whole-milk Greek yogurt.
- Use any cheese you like as long as it's melty. Gruyere is fabulous in this casserole, and I also like Monterey Jack.
- You can use fresh garlic instead of garlic powder.
Instructions
Scroll down to the recipe card for detailed instructions. Here are the basic steps for making this recipe:
Whisk eggs, heavy cream, shredded cheese, and seasonings.
Cook the sausage in a large skillet, breaking up the meat into small chunks as you cook it.
When the sausage is cooked, turn the heat off and stir in baby spinach leaves. The spinach will slightly wilt in the pan's residual heat.
Arrange the sausage and spinach mixture in the bottom of a baking dish, pour the eggs on top, and sprinkle the casserole with more cheese.
Bake the casserole for about 25 minutes in a 400°F oven. Cut it into squares and serve.
Expert Tips
- The red pepper adds a hint of spice. I don't find it overpowering. But if you're not into spicy foods, use just a pinch or omit it altogether.
- If you'd like to use frozen spinach leaves, defrost them first, and drain them REALLY well so they don't make the casserole watery.
Recipe FAQs
The classic ingredients are those that most of us consider breakfast foods, such as eggs, milk (or cream), a breakfast meat (such as sausage), and cheese.
Non-keto casseroles typically include bread. I like to add a veggie and especially enjoy spinach.
Yes. I prefer to bake it right after mixing the ingredients and putting them in the baking dish. But once baked, you can reheat the entire casserole, covered, in a 250°F oven, or cut squares and reheat them in the microwave.
Any sausage labeled as "breakfast sausage" is a classic choice since it's seasoned in a way that we associate with breakfast foods.
However, there's nothing wrong with using any sausage you like, enjoy, and have on hand. For example, Italian sausage is delicious in this casserole.
Serving Suggestions
I usually make this casserole for brunch and serve it with oven bacon, keto biscuits, or keto scones.
When we eat the leftovers on a weekday morning, we just grab a piece and have it with our morning coffee!
Storing Leftovers
The leftovers keep well for 3-4 days in the fridge in a sealed container. They taste great after a gentle reheat in the microwave at 50% power.
Sometimes, I cut myself a piece and eat it cold, straight out of the fridge!
You can also freeze this casserole for up to three months. I cut it into squares and freeze them in a freezer bag. If layering the pieces, separate them with wax paper.
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Recipe Card
Keto Breakfast Casserole
Ingredients
- 8 large eggs
- ¼ cup heavy cream
- ½ teaspoon Diamond Crystal kosher salt - or ¼ teaspoon of any other salt
- ¼ teaspoon black pepper
- ½ teaspoon garlic powder
- ¼ teaspoon red pepper flakes
- 1 cup cheddar cheese - shredded, divided; 4 ounces
- 1 pound breakfast pork sausage - raw
- 2 cups baby spinach leaves - 2 ounces
Instructions
- Preheat your oven to 400°F. Lightly grease a square 9-inch pan.
- In a large bowl, whisk the eggs with the heavy cream, salt, pepper, garlic powder, and red pepper flakes. Use a rubber spatula to mix in ½ cup of the shredded cheddar. Set aside.
- Heat a large 12-inch nonstick skillet over medium-high heat. There’s no need to add oil. Add the sausage and cook, stirring and breaking it up, until browned, 5-7 minutes.
- Turn the heat off and mix in the spinach leaves (you can leave them whole) just until they are very slightly wilted from the pan’s residual heat.
- Transfer the sausage-spinach mixture to the prepared baking dish, spreading it evenly on the bottom.
- Remix the eggs and pour them into the pan on top of the sausage mixture. If needed, gently stir the mixture inside the pan to evenly spread the sausage and spinach.
- Sprinkle the remaining ½ cup of cheese on top of the casserole.
- Bake the casserole until the eggs are set and the cheese is golden brown. In my oven, it takes 25 minutes.
- Allow the casserole to rest for 10 minutes before cutting it into nine squares and serving.
Video
Notes
- I divide the casserole into nine squares, so a serving is one square which is 1/9 casserole.
- You can use fresh garlic instead of powder.
- The red pepper adds a hint of spice. I don't find it overpowering. But if you're not into spicy foods, use just a pinch or omit it altogether.
- If you'd like to use frozen spinach leaves, defrost them first, and drain them REALLY well so that they don't make the casserole watery.
- The leftovers keep well for 3-4 days in the fridge in a sealed container. They taste great after a gentle reheat in the microwave at 50% power. Sometimes I cut myself a piece and eat it cold, straight out of the fridge!
- You can also freeze this casserole for up to three months. I cut it into squares and freeze them in a freezer bag. If layering the pieces, separate them with wax paper.
Nutrition per Serving
Disclaimers
Cup measurements refer to the standard American cup, which is 240 milliliters. Most of my recipes are low-carb (or keto) and gluten-free, but some are not. Please verify that a recipe fits your needs before using it. Recommended and linked products are not guaranteed to be gluten-free. Nutrition info is approximate, and the carb count excludes non-nutritive sweeteners. Nutrition info may contain errors, so please verify it independently. Recipes may contain errors, so please use your common sense when following them. Please read these Terms of Use carefully before using any of my recipes.
Vered DeLeeuw, LL.M., CNC, has been following a low-carb real-food diet and blogging about it since 2011. She's a Certified Nutrition Coach (NASM-CNC), has taken courses at the Harvard School of Public Health, and has earned a Nutrition and Healthy Living Certificate from Cornell University. Her work has appeared in several major media outlets, including Healthline, HuffPost, Today, Women's Health, Shape, and Country Living. 
Sharon
I have made this twice now and my family can’t get enough!! I use Le Gruyère cheese and added onions and mushrooms. It is perfect!! I’m going to try with diced ham and Swiss next time.
Vered DeLeeuw
Yum! Thanks for sharing your delicious tweaks, Sharon.
Molly
Excellent! A hit with family.
Vered DeLeeuw
Wonderful, Molly! Thank you for the comment.
Mandy
I have made this sooooo many times! It's my favorite breakfast! I use hot breakfast sausage and it's even more amazing!
Vered DeLeeuw
Hot breakfast sausage sounds so good! Thanks for the tip, Mandy. 🙂
Annette R.
This casserole was a hit!!! It came out perfectly. I added mushrooms, finely chopped green onions, a splash of Tabasco, a sprinkling of Adobo seasoning and a 1/4 cup of egg whites to make it all a bit fluffier. I couldn't be more delighted at how it turned out. So colorful, flavorful, filling and easy to make. I was able to package and stack the other portions in my 'fridge for quick breakfasts throughout the week. Thank you so much for crafting such a creative and healthy dish! Love it!!
Vered DeLeeuw
Yay! I'm so glad this casserole was such a big hit, Annette! Thank you for the comment and for sharing your mouthwatering tweaks. Yum.
Dee
Loved this casserole. I made it for my sister who is low carb with red peppers and onions instead. She is a picky eater but asked me to make again.
Vered DeLeeuw
I'm so glad this casserole was a success, Dee! Thanks for writing a review and sharing your tweaks.
Cathy
Can you double the recipe?
Vered DeLeeuw
Hi Cathy,
Yes. You can double the recipe and use a 9×13 inch pan. The baking time will be 30-35 minutes, but start checking after 25 minutes just in case.
Junque
I had family visiting on their way through town, and the only time they could visit was earlier in the day. I served this casserole with mixed berries and toast. It was a big hit. I didn't have spinach, but made it with thinly sliced onions and red bell peppers. I loved how fluffy and yummy it looked coming out of the oven. Thanks for posting this!
Vered DeLeeuw
I'm so glad you and your guests enjoyed this casserole, Junque!
Dianne
Absolutely delicious. My guests loved it.
Vered DeLeeuw
I'm so glad to hear that, Dianne! Thank you for leaving a comment.
Donna
If you add red pepper, onions and mushrooms, do you need to increase the egg count or heavy cream?
Vered DeLeeuw
Hi Donna,
Please saute the mushrooms until they release their liquid before adding them to the casserole. Otherwise, they can make the casserole watery.
Assuming you will add about 2 cups of veggies, I would add an extra egg and an extra tablespoon of heavy cream. Make sure to use a 9-inch baking dish, as an 8-inch one might be too small with these additions.
Linda
Can this casserole be frozen after it’s baked?
Vered DeLeeuw
Yes. To freeze the entire casserole, let it cool completely in the pan, then wrap it in a layer of cling wrap followed by a layer of foil. Freeze for up to three months. Thaw overnight in the fridge.
To freeze slices, let them cool, then place them in a single layer into a resealable freezer bag.
suzy Paden
Can this casserole be made ahead of time and cooked later?
Vered DeLeeuw
No, but you can bake it ahead of time. Once it's fully baked, cool it completely, wrap it in cling wrap, and keep it refrigerated for up to four days. Reheat individual slices in the microwave.
To reheat the entire casserole, remove the pan from the fridge, remove the cling wrap, and let it sit on the counter for 30 minutes. Cover the pan with foil and place it in a cold oven. Heat the oven to 325°F and keep the pan in the oven until the casserole is heated through, about 20 minutes.