This easy breakfast casserole recipe with eggs, potatoes and sausage is a perfect dish to serve for any meal, even beyond breakfast and brunch. It combines nutrient-dense eggs with spiced Italian sausage, oozy mozzarella or cheddar cheese, and sweet bell peppers for a tasty, balanced meal.

Preparing the Perfect Breakfast Casserole
Breakfast casseroles require a fair amount of cook time. But once the eggs are cooked, you don’t want to leave them sitting in the oven until the meat and veggies are tender. This would cause the eggs to dry out.
For this reason, all the filling components for this sausage breakfast casserole are cooked in advance before hitting the baking dish. I pre-blanch the potatoes in boiling water. Then I sauté the vegetable mixture and spiced sausage in a skillet. That way all parts are cooked by the time the eggs are set. This is also a good idea for your favourite quiche recipes or frittata recipes.
Another excellent way of ensuring perfectly tender, custard-like eggs in your easy breakfast casserole is to incorporate fat. In the case of this breakfast casserole, shredded mozzarella or cheddar cheese and a â…“ cup milk lighten up the egg mixture. They make the casserole delightfully fluffy.
Also, try not to overbake your eggs. A good rule of thumb is to cook the casserole until the middle has the slightest movement but is otherwise set. This casserole dish has a total time of 30 minutes for baking.

A Healthy Breakfast Casserole with Potatoes
I like to call this easy breakfast a healthy breakfast casserole because unlike most breakfast casserole recipes, it is made entirely from scratch and with only whole food ingredients. Instead of frozen hash browns, I make this breakfast casserole with fresh potatoes that are parboiled before baking.
I even make my potato breakfast casserole with sausage that I flavor myself by simply mixing ground pork with spices. Additionally, as with all shredded cheese recipes, I recommend shredding your own from a block of mozzarella or cheddar cheese to add to your egg mixture for this sausage egg potato casserole. It's so quick and easy to do (and cheaper), while you get to avoid all the added stuff (wood pulp etc.) in pre-shredded cheddar cheese.
A Clean-Out-the-Fridge Dish
Any egg recipe is excellent for using up leftovers in the refrigerator. An easy meal to prepare when you might be low on almost everything else. Generally, before a grocery shop, many people tend to have eggs, milk, blocks of mozzarella or cheddar cheese. And vegetables like broccoli and mushrooms, or greens like spinach that are just past their prime for fresh eating.
If you have some bacon or ham that need to be used, that works well in place of the sausage. This easy breakfast casserole is the place to use them whether you want to enjoy this baked casserole dish for breakfast or make breakfast for dinner. "Brinner" is a favorite around our house.

Substitutions for Restricted Diets
If you have a dietary restriction or are short on an ingredient, it is still possible to prepare this breakfast casserole recipe. For lactose-free diets, use your favourite lactose-free milk and cheese to make this a dairy-free egg recipe with excellent results.
For gluten-free, this casserole contains all traditionally gluten-free ingredients. However, you should always read cheese labels to make sure the cheese doesn’t contain wheat. Additionally, it is beneficial to ensure that the cheese wasn’t processed in a facility that also makes gluten-filled products.
Although cheddar cheese and mozzarella are recommended, you could really use anything that becomes similarly melty and stretchy. Swiss, Gruyere, and Gouda would all be excellent choices to add to your egg mixture. Don’t use drier cheeses like Parmesan or crumbly ones like goat cheese or feta. They won’t sufficiently melt into the egg mixture giving the breakfast casserole that creamy texture.

How Far in Advance Can you Prep an Egg Bake?
This egg casserole recipe can also easily be turned into a make-ahead breakfast casserole. Which is perfect to serve to guests who are staying overnight during the holidays or any other time of year. You can completely prepare everything the night before. In the morning, all you do is take the pan with the sausage egg casserole from the fridge and pop it in the oven.
Half an hour later a complete breakfast is ready to be served. Well, you should probably brew a pot of coffee (or tea) as well and some crusty bread with this casserole dish is never a bad idea either.
Tips for Preparing this Breakfast Casserole
- Don’t Overmix: When you mix the eggs with the milk, cheese, and black pepper, mix just until combined. If over combined, the egg mixture could souffle in the oven due to too much air.
- Rest the Casserole: Allow your casserole to rest for at least 10 minutes after coming out of the oven. This will make your egg bake easier to slice so that it comes out in clean, attractive pieces!
- Don’t Overbake: Just set, custardy eggs are heavenly. You can test whether the eggs are done by shaking the baking dish gently. If the eggs are completely set with just a slight jiggle in the middle, they will be perfect.
Storing Leftovers
You can store any leftovers of this egg casserole in an airtight container in the fridge. For food safety reasons, you shouldn’t keep cooked eggs in your fridge for longer than three or four days. But this overnight breakfast casserole likely isn’t going to last that long anyway.
The casserole can be frozen AFTER baking. Just wrap it well to prevent freezer burn or it taking on smells from the freezer. Then defrost in the fridge overnight and re-heat in the oven again. Or if you only want to reheat individual servings, be sure to cut up the casserole before freezing, and wrapping in smaller servings. Smaller servings can also be re-heated in the microwave or on the stovetop on low heat in a covered pan.
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Breakfast Casserole with Eggs, Potatoes and Sausage
Ingredients
- 20 ounces (600 g) potatoes peeled & cut into ½ inch cubes
- 1 pound Italian sausage*
- 1 onion diced
- 1 red pepper diced
- 3 garlic cloves minced
- 2 cups shredded mild cheese from a block of mozzarella or mild cheddar
- 6 large eggs
- â…“ cup milk
- ¼ teaspoon black pepper
- sliced green onion
Instructions
- Preheat oven to 375 degrees F. Cook the potato dices in salted boiling water for about 5 minutes. Drain and let cool.
- Remove casings from sausage, unless you are making your own mix like me. Heat a large skillet to medium-high and cook the sausage until browned. Break it up in the process. Remove from skillet with a slotted spoon. Leave 1 tablespoon of grease.
- Cook the onion and red pepper in the sausage grease for about 5 minutes. Add the garlic and cook a couple more minutes. Fill into a large baking dish (9x13 inches) together with sausage and potato dices.
- In a large bowl, whisk together the eggs, milk and black pepper. Add 1.5 cups of the shredded cheese and stir to combine everything. Pour into the baking dish.
- Sprinkle the remaining cheese on top, cover with foil and bake for 20 minutes. Uncover and continue baking for 10-15 more minutes.
- Let the breakfast casserole rest for a few minutes. Add sliced green onion and serve hot.
Notes
Nutrition
Recipe inspired by Gimme Some Oven
Tanya
These are a family favorite at our house. I tend to try to add too much to it though. Your picture and recipe help encourage me to keep it simple. It looks fantastic!
Regina
Thank you Tanya! So glad to hear your family enjoys the breakfast casserole recipe. It's perfect for the holidays
stephanie
If I cut this recipe in half, and used a smaller baking dish, would i need to change the baking time at all?
Regina
The baking time should be very similar. Maybe start checking about 10 minutes earlier though just to be sure.
Joe
I somehow got lassoed into cooking breakfast for church next sunday. This looks good for a large group so I'm going to give it a try and see how it goes. uh boy wish me luck; not that the recipe needs it, but my cooking skills do.
Regina
Let me know how it goes/went! Did you multiply the breakfast casserole recipe
Joe Rimkus
Everyone loved the breakfast casserole, huge success. Perfect recipe for a large crowd. I ended up using 30 eggs, 7 lbs of potatoes, 2lbs cheese, 3 lbs breakfast sausage, mushrooms and olives.
I'll probably do it again, will change one thing: split the mixture into two pans instead of one big one. It took too long to cook such a large amount, outside cooked sooner than the middle. What I had to do is stir the mixture after 45 minutes so it heat evenly.
Daniella
Hi Regina! I love this recipe! If I wanted to make it as a meal prep for the week, how long can I keep it in the freezer?
Regina
Hi Daniella, if properly wrapped it could be good in the freezer for several months. If you mean the fridge, it's 4 days
Melissa Torres
Love the addition of the potatoes. I make something like this with a croissant crust and I always think it's a waste of calories when I'd rather have more of the other ingredients. This is brilliant!
Regina
The croissant crust sounds intriguing though!
Gwen
I am heading to a family reunion (quite rustic). I was wondering about cooking this breakfast casserole ahead of time and freezing it. I will have an oven available at the reunion. I would make it as described and then freeze it. I would then thaw it and reheat it in the oven. Any advice on this or any changes you would make to have this be successful? Thanks!!
Regina
That sounds like a good plan to me. If the casserole is fully thawed I don't think it should take too long to reheat (no risk of drying it out)
Lisa Moss
I made this easy breakfast casserole yesterday for Easter and it was a hit.
No leftovers! I used Jimmy Deans hot sausage to give it a kick. I forgot to add the green onions before serving because I got sidetracked but will definitely be making it again. I’ve made breakfast casseroles in the past and they were just ok. This was great. Thank for this recipe!
Lisa Moss
Forgot to rate it but I’d give it 5 stars!
Regina
Thanks for that!!
Regina
Yay I am so happy to hear this was enjoyed by everyone!!
Peachy
For your own breakfast sausage recipe, does 1t means tbsp or tsp?
Regina
A lower case t means teaspoon. Tablespoon would be capital T
Meg
Quick question! For the make ahead option, your instructions say "...take from the fridge and pop it in the oven. Continue with the instructions in the middle of 5." So, do you bake for 20 minutes, then put in the fridge and heat the rest of the way in the morning, or just assemble and store in the fridge and bake in entirety in the morning? Thank you!
Regina
Sorry, I will make this more clear in the instructions. Sprinkle the cheese on top, cover with foil and put in the fridge overnight. Then bake for 20 minutes covered, and 10-15 minutes uncovered.
Rachel Brink
What kind of potatoes are you using? Shredded hash browns? Cubed? Fresh or frozen?
Regina
I use fresh potatoes that I peel and cube
Heidi
Hello, the breakfast casserole sounds fantastic would love to make it for work Monday morning and would love to use my casserole crockpot. Have you ever tried cooking this in a crockpot?
Regina
I have never tried this in a crock pot though I have heard of slow cooker egg casseroles. I don't see why this one wouldn't work the same way
Allie
This breakfast casserole sounds delicious! I'm wondering if I could cut it in half as it's just for two and utilize a 8x8 dish. Also maybe reduce the peppers by a little and add chopped tomatoes.
Regina
Yes, you can definitely cut in half and make it in an 8x8 pan. And the veggies are totally interchangeable in this dish
Greg
If i use a 8x8 dish with the complete recipe, do i cook it longer or does it matter?(already preped in the dish)
Will i have a mess now?
Regina
Hi Greg, sounds like this reply will come too late for you. But for anyone else trying to bake this easy breakfast casserole in a smaller dish, you'll need to add probably 10 minutes to the baking time or check until the eggs are more or less set.
jasmyn
Hey what is the nutrition info for this like Cal sodium carb serving size etc
Tatiana Temple
I am making this tonight for dinner and want to add some spinach and skip the peppers because my husband won't eat them. Should I just use the same amount of spinach that it calls for with peppers? Also, I should just put the spinach in raw, correct?
Regina
Love that you are making this for dinner! Sorry this may be a little late, but yes use raw spinach, maybe cut up a bit. Once diced pepper is probably about 1 - 1.5 cups worth, so yes I would probably do about the same amount of cut up spinach
Grace
Thank you, however I followed the direction to bake, but was still not complete baked using the direction. What am I doing wrong? I also prepped it the night before. We have an electric stove.
Please help
Regina
It may be your oven temperature runs a little lower than indicated? I would just continue baking until the eggs are more or less set
Grace
Hi does it matter if I use metal or glass casserole dish when you prep it the night before?
Regina
I've done both with no issues. I wouldn't use a scratched up rusty metal dish though
Michelle @ Vitamin Sunshine
Yum! I love the tiny hand sprinkling cheese in your video 🙂 I am making my first video and I think I need to stop trying to make it perfect and just publish. I have retaped it 4 times now and still am not totally happy. We have like 9 batches of granola bars in my freezer from all of it.
Regina
Love that you noticed my toddler helping out. It wasn't intentional. Usually I try to keep her faaar away when I shoot video. She snuck in here and when I reviewed the clips I thought it was quite cute actually.
Yes! Stop trying to be perfect. My best performing videos are definitely not my best work. A lot has to do with the type of recipe as well. And I'd gladly take a few of those granola bar batches off your hands 😉
Christine
What would the calorie count be per serving? Around about
Sydne
Just tried this breakfast casserole. YUUUUUUM!
Regina
Awesome! Thank you for your feedback, Sydne 🙂
Jenn
It said prep time was only 15 min. Apparently you didn't use all fresh ingredients as i did. Cause it just took an hour from the time I started perping to putting it in the oven.
Jill
Same with me. Between peeling and dicing the potatoes, onions, peppers, garlic and shredding the cheese, sauteeing the sausage and chopped veggies, boiling the potatoes, it took much longer than 15 minutes to prep. Closer to 45 minutes.