Christmas mornings are a curious blend of frenzy and magic in our home. The children run down the stairs to admire the tree and gaze in awe at the piles of ribboned gifts that appeared overnight. And, I don’t want to miss a thing. That’s why every Christmas, I make a special brunch – one that takes almost no energy because it’s all been prepared ahead. And the center every Christmas is a super simple, Make-Ahead Breakfast Casserole.
Packed with vegetables and good quality sausages, it pairs beautifully with a light fruit salad. And all you have to do is tuck it in the oven about 30 minutes before you plan to eat.
Jump to Recipe | Formula | Sealing and Freezing | Tips | Variations
What is a breakfast casserole?
A breakfast casserole is an egg dish that you can make ahead for breakfast. Most casseroles include cheese, vegetables, meat and a starch like potatoes or bread.
They’re easy to prepare and can feed a crowd. In addition, breakfast casseroles reheat very well. So, you can easily make it ahead, tuck it in the freezer and then reheat it when you’re ready to serve family and guests. Accordingly, it’s a perfect dish to serve for holiday brunches. That way, you’ll spend more time with your loved ones and less time in the kitchen.
What’s the formula?
Make-ahead breakfast casseroles sometimes develop a rubbery texture when they’re over-baked either during the initial bake, or when reheated. So, for smooth texture follow a ratio of 1 whole egg to 1/2 cup cream or other dairy. It’s that easy.
In addition, make sure to cook most of the water out of the vegetables you add to the casserole. That way they won’t leak water into the casserole and break your custard. If you keep to the rules, you’ll have a gorgeous casserole every time you bake.
Freezing, Sealing and Reheating
By making a breakfast casserole ahead, you’ll save loads of time in the morning and can spend more of that time with your friends and family – and less in the kitchen. That’s because the work’s already done.
To make it in advance, you’ll first prepare the egg casserole and bake it as you normally would. And then you’ll freeze it. For the best results, use a double-freeze method that allows you to vacuum seal the casserole. As a result, your casserole will stay fresh longer and taste better. Plus, you won’t have to worry about freezer burn.
First, bake your casserole and allow it to cool to room temperature on the countertop. Next, tuck the casserole, pan and all, in the freezer. Allow to freeze until just solid – about 2 hours. Next, vacuum seal the casserole in its pan. Return it to the freezer where it should keep up to 1 year.
The night before you plan to serve the breakfast casserole, let it thaw in the fridge. Next, sprinkle it with cheese, tent it with foil and let it come to temperature in the oven.
Breakfast Casserole
Ingredients
- 1 tablespoon extra virgin olive oil
- 1 medium yellow onion (chopped fine)
- 6 ounces breakfast sausage
- 1 cup sliced button mushrooms
- 3 large eggs
- 1 1/2 cups sour cream
- 1 1/2 teaspoons finely ground real salt
- 1/2 teaspoon ground black pepper
- 4 medium green onions (chopped fine)
- 1/2 cup shredded cheddar cheese (divided)
Equipment
- 1 1/2 Quart Baking Dish
Instructions
Make the Breakfast Casserole.
- Heat the oven to 350 F.
- Warm the olive oil in a skillet over medium heat, and then toss in the onions. Sauté them in the hot oil until deeply fragrant and beginning to caramelize, about 10 minutes. Stir in the breakfast sausage, and continue cooking with the onion until cooked through and well browned – about 8 minutes. Toss in the mushrooms, and sauté until browned and cooked through. Turn off the heat and allow the filling to cool.
- Whisk the eggs with sour cream, salt, pepper and green onions together with half the grated cheese.
- Spoon the filling into a baking dish, and then pour in the egg mixture. Bake for 45 minutes, until puffed with a slightly wobbly center. Allow the casserole to cool to room temperature, and then transfer to the freezer at least 2 hours and up to overnight.
Prepare the casserole for long-term freezing.
- Remove the casserole from the freezer, and sprinkle it with the remaining cheese. Tuck the casserole in its dish into a FoodSaver vacuum seal bag, and vacuum seal. Transfer to the freezer, and serve within 1 year.
Finishing the casserole.
- The night before you plan to serve the casserole, transfer it from the freezer to the fridge. Let it thaw, refrigerated, at least 8 hours and up to 24 hours.
- Heat the oven to 350 F, and place the casserole on a baking sheet. Tent with foil, and bake for 30 minutes, or until the casserole reaches an internal temperature of 160 F.
- Turn on the broiler to high, and remove the foil. Allow the cheese to brown under the broiler, 3 to 5 minutes. Serve warm.
Grab a FoodSaver on Sale!
We use the FoodSaver FM2000 Vacuum Sealer System in making this Breakfast Casserole. It’s available at Walmart with special rollback pricing to $69. Check it out here.
Variations
Once you get the hang of this Make-Ahead Breakfast Casserole, you can adjust the basics – adding different cheeses (or none at all) and choosing new seasonal vegetables, too. Always remember to keep cook the vegetables well to keep your custard from breaking.
- Sundried Tomatoes, Goat Cheese and Thyme work well in place of sausage and mushrooms. Chop the tomatoes finely for the best texture.
- Kale, Garlic and Potatoes go well together. Just remember to cook your kale well, and give it a squeeze to reduce the water content before you toss it in with the eggs.
- Bacon and Onion are a classic combination, especially when paired with full-flavored Gruyere cheese.
- Spinach and Smoked Salmon are also a nice combination. Remember to give your spinach a squeeze to reduce its liquid.
Jennifer Morgan-Binns says
I’ll look into the specialized containers!
4waystoyummy says
Thank you for this recipe. When my son was little I found a great contribution(and distraction) that he could make to our Christmas breakfast. The Elves and Fairies would leave a small bag of juice oranges and a hand twist juicer(these cost about $2)under the tree for him to make a few small sample glasses of fresh juice. I am not usually a fan of drinking juice but it was special and tasty. And in my preschooler’s own words, “I made the best part of breakfast.” Now there’s a feel-good memory!
Jenny says
That is such a charming story!
Terry says
What size of dish are you using? We normally use a 9 x 13, but also use 12 eggs. Thanks for all of the information on freezing! I didn’t know you could freeze an egg casserole.
Jenny says
This was about 1 1/2 quarts, I believe.
Spice Lady says
Hi Jenny- thanks for this recipe.
I batch cook for a relative who doesn’t thaw food for any length of time. My question is — is there a way to take it directly from freezer to oven that would preserve the casserole custard and taste?
Thank you.
Jenny says
Hi! You can take it from the freezer directly to the oven, but it’ll need to cook 60-90 minutes.
Jennifer Morgan-Binns says
Jenny, I love this recipe. It seems easy and delicious. I also appreciate the tips for baking. However your storage ideas using single use plastic for vacuum sealing are very disappointing. The use of single use plastic is very problematic for environmental reasons as I’m sure you were aware. I encourage you to use your platform to advocate less plastic use even if it means possibly freezer burning a breakfast casserole. This is a serious issue. I’d deeply appreciate a reply. Be well
Jenny says
Hi Jennifer! Thanks for your comment. I really love our vacuum sealer, and we use it often – for curing meats, for fermentation, and to preserve the harvest efficiently and without loss of flavor. There’s many ways you can (and we do) reuse the vacuum seal bags, and there’s options to use a vacuum seal system without bags by using specialized containers. While I appreciate your suggestion as to how you envision I should use my platform, I’ve always used to to share things I find valuable and useful in my daily life and will continue to do so. Of course, there’s a great opportunity for you to develop a platform and use it to explore ideas and tools you find valuable too.
Maggie A. says
The vacuum bags are not single-use. You can wash & reruse them numerous times. I have been using them for many years & I have seldom needed to dispose of any of them.
LIsa Damian says
I bake/roast my veggies (with a bit of salt, pepper, olive oil and a dash of balsamic vinegar) before adding them to egg dishes. It gives the sugars a chance to caramelize for more complex flavors and removes a great deal of the moisture.