This Make Ahead Breakfast Casserole with Sausage and Veggies makes mornings easy. Cook it the night before, let it sit overnight, then pop it in the oven the next morning – you’ve got a simple and delicious meal that also happens to be gluten free!
Hi everyone! It’s Taryn from Hot Pan Kitchen. Today I’ve got a great make ahead breakfast recipe that works for a lazy Sunday morning or to complement an Easter brunch. Cook the filling the night before, add the egg mixture, then let it sit overnight. All you have to do in the morning is heat up your oven and let it bake!
This recipe uses sauteed red onion and fennel, plus sausage and spinach. It’s packed with veggies and has loads of flavor. Of course, if you need something that’s more bite size you could always try these Healthy Breakfast Make Ahead Muffins, but if you’ve got a table to feed, this recipe is where it’s at.
To help you as you’re making this, read on for some answers to common questions about breakfast casserole.
How Long Will Breakfast Casserole Keep
Breakfast casserole will keep in the fridge for several days, as long as it’s stored in an airtight container or wrapped in plastic wrap.
Can Breakfast Casserole be Frozen
Breakfast Casserole can be frozen, however I would recommend cooking it until just barely done then freezing it. Store tightly wrapped or in an airtight container in the freezer for several months. Defrost before cooking, then pop in a 350 degree F oven to bake until cooked through.
Can Breakfast Casserole be Reheated
Breakfast casserole can be reheated in the microwave or in the oven.
What to Serve with Breakfast Casserole
There are lots of options to serve with a breakfast casserole! Muffins, breads, and pancakes are great ideas. Take a look at these recipes to round out your meal:
How to Make Breakfast Casserole
First you’ll want to cook the sausage in a non-stick pan over medium heat. Break it up with a wooden spoon or spatula so it cooks faster and so it will be easier to spread in the casserole dish.
While the sausage is cooking, you’ll want to slice the onion and fennel. If you’ve never cooked with fennel before, it has a bit of an anise (or black licorice) taste when raw, but it sweetens when it cooks.
You’ll want to cut the stems and fronds off and just use the bulb. Thinly slice both it and the onion then set aside.
Once the meat is cooked, remove it from the pan with a slotted spoon and place it on a paper towel lined plate. You want to leave the grease in the pan to cook the veggies.
Next place the sliced onion and fennel into the pan and cook until translucent and browning, 15-20 minutes. Be sure to stir well so nothing burns!
As the veggies are cooking, make your egg mixture. Combine the eggs, milk , ½ teaspoon of kosher salt, and ground black pepper into a bowl and whisk until thoroughly combined.
You’ll also want to grease a 9×13 baking dish at this point. Then once the veggies are done cooking, add in the fresh baby spinach and cook until wilted, 3-4 minutes
Now onto assembly!
Start with the sausage and spread it in an even layer in the baking dish
Next add the veggie mixture and again do another even layer (as best you can).
Pour the egg mixture into the dish as evenly as you can, making sure a good portion of the veggies are covered with egg.
Place a piece of plastic wrap over the dish to cover completely, then refrigerate overnight. When you’re ready to bake it in the morning, take it out 20-30 minutes ahead of time to let the dish warm up. Preheat the oven to 350 degrees F and bake it for 35-40 minutes (until the middle is cooked through).
More Breakfast Ideas
If you’re looking for more breakfast recipes, be sure to check these out from Fox and Briar:
Crab, Asparagus, and Leek Quiche
Make Ahead Breakfast Burritos (Freezer Friendly)
Sausage and Kale Make Ahead Egg Muffins
Or take a look at these from Hot Pan Kitchen!
Easy Sheet Pan Breakfast
Roasted Tomato, Kale, & Goat Cheese Breakfast Frittata
Potato Breakfast Hash with Sausage, Mushrooms, & Peppers
If you try this recipe, be sure to comment and rate it below! And I’m sure you’re already following Meghan on Instagram, but I would love it if you would follow along with me on Instagram too! I post recipes, kitchen tips, and ways I’m trying to teach my kids to cook.
Make Ahead Breakfast Casserole
- 1 pound pork breakfast sausage
- 1/2 red onion
- 1 fennel bulb
- 1 teaspoon kosher salt divided
- 5 ounces fresh baby spinach
- 12 eggs
- 1/4 cup milk
- 1/4 teaspoon ground black pepper
- Cook the sausage in a non-stick pan over medium heat until no longer pink (5-7 minutes), breaking it up as it cooks with a wooden spoon or spatula
- While the sausage is cooking, thinly slice the fennel bulb and onion. Set aside.
- Once the sausage is done, remove with a slotted spoon on a paper towel lined plate to drain, leaving the grease in the pan.
- Place the thinly sliced fennel and onion into the greased pan, along with ½ teaspoon kosher salt and cook until both are turning translucent and starting to brown, about 15-20 minutes. Be sure to stir every couple of minutes so the veggies don’t burn.
- While the fennel and onion are cooking, crack eggs into a large bowl. Pour in the milk, ½ teaspoon of kosher salt, and ground black pepper. Whisk together until fully combined. Also grease a 9x13 baking dish and set aside.
- Once the fennel and onion are done cooking, place the baby spinach in the pan and cook until wilted, about 3-4 minutes
- Place the cooked sausage in an even layer in the baking dish, then place the veggies over the sausage in an even layer. Next pour the egg mixture over everything, making sure most of the veggies are covered (it’s okay if some parts are above the egg).
- Put saran wrap over the top of the dish and put it in the fridge overnight. Alternatively, you can also cook it right after making it, if you wish (just skip step 9).
- In the morning, take the baking dish out of the fridge and let come up to room temperature (about 30 minutes).
- Preheat the oven to 350°F, then bake the dish in the oven for 35-40 minutes. Insert a toothpick in the middle to make sure it’s cooked through. Let sit for 5 minutes to cool slightly before serving!
Ashlyn @ f5 method says
This looks delicious! I love making breakfasts casseroles ahead of holidays or big events for an easy and quick breakfast and the flavors of yours look delicious!