This delightfully easy Breakfast Casserole is layered with earthy mushrooms, onions, peppers, potatoes, baby spinach, fluffy eggs and melty, gooey cheese. Serve this casserole for breakfast, brunch or even dinner with a green salad on the side.
If you’re in need of an elegant and easy casserole that will feed a hungry crowd in the morning, this one is spectacular. It has all the savoury goodness everyone is craving—bacon, cheese, eggs, veggies, and hash brown potatoes—conveniently mixed into one luscious dish.
Like most breakfast casseroles, this one too can be prepared ahead so the next morning you can just pop it in the oven while still in your PJ’s. Let it bake until puffed and golden at the edges then serve it while it’s still hot, creamy, and melty. Simple enough, and oh-so-good.
Why You’ll Love This Recipe
- Feeds a crowd – As part of a brunch or breakfast spread, this casserole will serve 12. If serving as a main dish, it will likely serve 6.
- Loaded with veggies – With plenty of spinach, mushrooms, peppers and onions, this casserole does not skimp on the veggies.
- A filling and substantial casserole – The addition of potatoes, along with the cheese and all the veggies, helps build up this casserole to make it hearty and satisfying.
- Loaded with flavour – Filled with bacon, veggies and plenty of gooey cheese, there is nothing bland or one-note about this casserole.
- Make-ahead – Though there is a bit of preparation that goes into making this casserole, it can all be done the night or two before you are planning on serving it.
- So versatile – There are endless possibilities for customizing this casserole. Omit the bacon to make it vegetarian, swap out some of the veggies for others you might enjoy more, use any kind of cheese, use sausage instead of bacon.
- Serve it for dinner! This breakfast casserole makes a fun and delicious meal for dinnertime.
- Gluten-free – A lot of breakfast casseroles are made with bread. In this recipe we use potatoes as our starch which means the casserole is completely gluten-free.
Ingredients And Notes
- Eggs – This recipe calls for 12 large eggs which makes a nice fluffy and hefty casserole.
- Potatoes – For convenience, here we use shredded or diced frozen hash brown potatoes. No need to thaw them. However, especially around the holidays, they’re sometimes hard to find. If you need to use fresh potatoes, like I did in these photos, see section below for instructions.
- Vegetables – For this breakfast casserole we use onions, garlic, mushrooms, bell peppers, and spinach. Because most of these veggies can be watery, they need to be par-cooked to drive off some of the moisture before cooking. This will also make them mush more flavourful.
- Bacon – For a special holiday breakfast, I give them what they want. That’s usually bacon. In this breakfast casserole you could use sausage, pancetta, or even smoked salmon, instead.
- Cheese – Mixing in grated cheese adds loads of flavour and melty gooeyness. I use grated aged cheddar but just about any cheese will work; Guyère, Fontina, mozzarella, goat cheese, feta, smoked Gouda, etc.
- Whole milk or half and half – You can use whole milk in this casserole but half-and-half adds a luxurious richness that to the dish.
- Fresh herbs – Optional, but I like to add a bit of fresh herbs like chives and dill, for a pop of colour and herbacous flavour.
Can I use Fresh Potatoes Instead Of Frozen?
I love to use fresh potatoes in my breakfast casseroles. Frozen potatoes are convenient but I don’t always have them in my freezer whereas I almost always have fresh potatoes. If you prefer to use fresh potatoes, here’s what to do:
Substitute one medium potato for each cup of frozen potatoes. Prick each potato several times with a fork, then place in the microwave on a paper towel. Microwave on HIGH for 8 to 10 minutes, or until the potatoes are just barely tender. Once cool enough to handle, shred, or dice and proceed with the recipe.
If you prefer not to use a microwave, this is a good tutorial on how to par-cook potatoes.
Another favourite dish to serve a crowd during the holidays is this Everything Bagel Breakfast Casserole. It is absolutely delicious and always a huge hit.
How To Make This Easy Breakfast Casserole
There is a bit of prep involved to make this dish but as previously mentioned, it’s all very straight forward and can be done in advance.
- Cook the bacon, set aside on a paper towel-lined plate.
- Sauté the vegetables then stir in the frozen potatoes. Spread evenly in a large casserole dish and sprinkle the bacon and most of the cheese over top.
- In a large bowl, whisk the eggs, milk and salt and pepper. Pour over the vegetables and sprinkle with some of the fresh herbs, if using.
- Bake in preheated oven until edges are golden brown and the casserole has puffed up beautifully.
- Cool for 5-10 minutes before slicing. The casserole will have deflated a bit once cooled but it should still be light and airy.
Serving Suggestions
If serving this breakfast casserole as part of a brunch spread, it would pair nicely with a fruit salad, avocado slices, bagels and cream cheese, and smoked salmon.
It would also be great alongside this chia pudding, or these pumpkin muffins. For an easy, light dinner, I like to pair it with a green leafy salad and nothing more.
Oh, and last but not least, don’t forget the hot sauce!
Make Ahead Tips
You can assemble the entire casserole before baking it. Cover tightly with plastic wrap or aluminum foil and refrigerate overnight (but no longer). If you’d like to get some prep work done a few more days in advance, here’s what to do:
- Up to 2 days ahead, cook the bacon and vegetables and refrigerate in separate containers. Grate the cheese and refrigerate in a separate container. (If using frozen hash browns, don’t add them yet.)
- When ready to bake, layer the veggies, frozen hash browns, bacon and most of the cheese in the casserole, as per recipe.
- Whisk together the eggs, milk, salt and pepper and pour over top. Sprinkle with remaining cheese.
- Bake as instructed.
Storage Tips
- To Store: Refrigerate leftovers in an airtight storage container for up to 3 days.
- To Reheat. Reheat leftovers in a baking dish, in a preheated 350ºF oven until warmed through.
More Easy Breakfast Ideas
- Shakshuka
- Baked French Toast
- Everything Bagel Breakfast Casserole
- Baked Oatmeal with Blueberries
- Epic Summer Frittata
If you give this Easy Breakfast Casserole recipe a try, please feel free to leave a comment and/or a star rating below. We appreciate and welcome all your feedback. Thank you!
Easy Breakfast Casserole with Vegetables
Ingredients
- 4 slices thick-cut bacon, cut crosswise into 1/2-inch pieces
- 8 ounces cremini mushrooms thinly sliced
- 1 large yellow onion thinly sliced
- 1 teaspoon olive oil (only if needed)
- 3 garlic cloves minced
- Kosher salt and freshly cracked black pepper
- 2 bell peppers diced (I use red peppers)
- 3 cups fresh baby spinach
- 4 cups frozen shredded, or diced, potatoes* (do not thaw)
- 1 1/4 cup shredded cheddar cheese, divided
- 12 large eggs
- 2/3 cup (160ml) milk or half-and-half*
- optional garnish: chopped dill and/or chives
Instructions
- Arrange a rack in the middle of the oven and heat to 375°F. Coat a 9×13-inch baking dish with baking spray or olive oil; set aside.
- In a large skillet, cook the bacon over medium heat, stirring occasionally, until browned and crisp. Using a slotted spoon, transfer bacon to a plate lined with paper towels; set aside.
- Remove all but 1 tablespoon of bacon fat from the skillet and heat over medium-high heat.
- Add the mushrooms and cook, undisturbed for 2 minutes. Give them a toss and cook for another 2 minutes. Lower the heat to medium, add the teaspoon of olive oil if skillet seems dry, then add the onions, garlic, and 1/2 teaspoon of salt. Cook, stirring occasionally, until onions are translucent, about 3 minutes. Stir in the peppers and cook, stirring occasionally, for about 1 minute. Add in the spinach and once wilted, remove from heat. Stir in the frozen shredded (or diced) potatoes and toss with all the veggies.
- Transfer vegetable mixture to prepared baking dish and spread into an even layer. Sprinkle cooked bacon and 1 cup cheese evenly over top.
- In a large bowl, whisk the eggs, milk, 1 teaspoon salt and pepper to taste. Pour over the vegetables. Sprinkle remaining cheese evenly over the top.
- Bake the casserole, uncovered, until edges are golden brown and the casserole has puffed up beautifully, 45 to 55 minutes. (The tip of a knife inserted in the middle should come out clean.) Let sit for 5 or 10 minutes. Garnish with fresh herbs, if using, then slice and serve hot.
Notes
- Potatoes – For convenience, here we use shredded or diced frozen hash brown potatoes. No need to thaw them. However, especially around the holidays, they’re sometimes hard to find. If you need to use fresh potatoes, like I did when I photographed this recipe, here’s what to do: Substitute one small/medium potato for each cup of frozen potatoes. Prick each potato several times with a fork, then place in the microwave on a paper towel. Microwave on HIGH for 8 to 10 minutes, or until the potatoes are just barely tender. Once cool enough to handle, peel the potatoes and shred on a box grater. You can also dice the potatoes, if you prefer.
- Milk – You can use whole milk in this casserole but half-and-half adds a luxurious richness to the dish.
- Make Ahead: The casserole can be completely assembled, covered tightly with plastic wrap or aluminum foil, and refrigerated overnight (but no longer) before baking. Uncover before baking and add a few extra minutes of baking time.
- To Store: Refrigerate leftovers in an airtight storage container for up to 3 days.
- To Reheat. Reheat leftovers in a baking dish, in a preheated 350ºF oven until warmed through.
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