Easy Egg Casserole Recipe – Make Ahead Breakfast

Egg Casserole truly is a comforting classic! With this easy breakfast recipe, soft eggs, gooey cheese, and fresh vegetables come together in perfect harmony, offering a dish that’s both filling and delicious. Be it a relaxed family morning, a festive holiday brunch, or just a lazy weekend meal, this easy breakfast casserole promises simplicity and flavor in every bite. 

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Why You Will Love Making Egg Casserole

• Egg casserole isn’t just a feast for the taste buds; it’s also a powerhouse of nutrition! With eggs as the star of the show, every bite offers a hearty dose of protein, keeping you satiated and energetic throughout the morning. Add in the vibrant bell peppers, and you’ve got yourself a dose of vitamin C to kickstart your day in the healthiest way possible. And let’s not forget the calcium from that beautifully melted cheese, ensuring that your bones get the love they deserve.
• Feel free to get creative with your vegetable mixture. Try tossing in some leftover vegan ham for an extra punch of flavor. Whether you’re a fan of sharp cheddar, prefer a milder Swiss cheese, or want to spice things up with pepper jack, the choice of cheese is all yours! If you enjoy a bit of heat, try adding a dash of hot sauce for a spicy kick. And if you’re craving more veggies, a medley of mushrooms, spinach, and even frozen hash browns to make a hash brown egg casserole would be absolutely delicious.
• Make-ahead breakfast casserole recipes are a true lifesaver. The beauty of this egg breakfast casserole lies in its convenience to be prepared ahead of time. Simply whip up the egg mixture, pour it into your greased casserole dish, and pop it into the fridge. On the following morning, all that’s left to do is bake the overnight breakfast casserole to perfection. 
• Whether it’s Easter brunch, Christmas morning, or a simple weekday meal, this easy breakfast casserole recipe fits seamlessly into any occasion. The ease with which it caters to a crowd makes it a go-to for family gatherings and friendly get-togethers. Plus, its warm, comforting nature makes it a hit even with the little ones. It’s the BEST breakfast casserole recipe!
• Navigating breakfast options can be a bit tricky for those on a gluten-free diet. Thankfully, this easy egg bake naturally treads into gluten-free territory, ensuring that everyone, regardless of dietary restrictions, can dive into its deliciousness without a second thought.

Ingredients You’ll Need

You’ll need all the ingredients in the photograph below.

How to Make Egg Casserole with Step-by-Step Instructions

A complete printable recipe and the measurements in both US customary and metric are available in the recipe card below.

Preheat and Prep

First things first, let’s get that oven warming up by preheating it to 180ºC (approximately 350ºF for those using Fahrenheit).

While the oven is heating, grab your baking tray and give it a good spray with cooking oil to ensure our egg casserole doesn’t stick during the baking process.

Creating the Egg Mixture

In a large bowl, combine your eggs, sour cream, and milk, whisking them together until they’re beautifully blended.

Add 1 ½ cups of shredded cheddar cheese (or your cheese of choice), and season with some salt and pepper. 

Sautéing the Veggies

Heat a large skillet over medium heat and add a dash of olive oil. Toss in your sliced green onions, diced green pepper, red bell pepper, and red onion.

Rest and Serve

Once your egg casserole is beautifully baked, resist the temptation to dive right in! Let it rest for a few minutes. This allows the flavors to meld together and the cheese to get to that perfect level of gooeyness.

Slice it up, serve, maybe add a sprinkle of green onion, and watch as the faces around your table light up with that first flavorful bite!

Recipe Notes and Expert Tips

• Cheese: When it comes to cheese, the world is your oyster! While our recipe calls for cheddar, don’t be afraid to mix it up. A blend of sharp cheddar and mild Monterey jack, or a sprinkle of feta cheese, can bring a new dimension to your egg casserole. For a spicy kick, pepper jack cheese is perfect. For a luxurious, creamy texture, try adding a bit of cream cheese to your egg mixture.
• Veggie Variations: The vegetable mixture in this egg casserole is super versatile. Feel free to swap in your favorites or whatever you have on hand. Think mushrooms, spinach, zucchini, or even a bit of kale. If you’re using veggies with a higher water content, like tomatoes or fresh spinach, be sure to sauté them first to remove excess moisture and avoid a soggy casserole.
• Veggie Meats: If you’re looking to add a bit more heft to your egg casserole, cooked vegetarian breakfast sausage, vegetarian diced bacon, or chopped ham made out of tofu are delightful additions. Make sure that any faux meat you add is fully cooked before incorporating it into your egg mixture. This maintains the casserole’s texture and ensures even cooking.
• Spice It Up: For those who enjoy a bit of heat in their breakfast, try adding a diced jalapeño to your sautéed veggies, or a sprinkle of red pepper flakes into your egg mixture. A dash of hot sauce on top can also provide a lovely kick without altering the original recipe too much.
• Making it Low-Carb or Keto-Friendly: At just 6g net carbs per serving, this easy recipe is already perfect for a low-carb or keto diet. If you want to experiment with ingredients, be mindful of the vegetables you choose. Opt for low-carb options like spinach, mushrooms, and bell peppers. Additionally, consider adding extra cheese or cream to increase the fat content.
• How Can I Make Sure My Casserole Is Not Watery? To avoid a watery casserole, thoroughly cook and drain any high-moisture vegetables (like mushrooms or tomatoes) before adding them to your egg mixture. Additionally, fully thaw and drain frozen ingredients, if you choose to use them. This prevents additional moisture from being released during baking.

How to Store Leftover Egg Casserole

Here are some useful storage suggestions if you find yourself with leftover breakfast casserole.

Keeping it Fresh: Refrigerating Your Leftovers

Simply allow the casserole to cool completely to room temperature. Once cooled, place it in an airtight container or wrap it securely with plastic wrap and pop it into the refrigerator.

Properly stored, your breakfast casserole will maintain its freshness for up to 4 days. It’s a fantastic make-ahead option for easy, breezy breakfasts throughout the week.

Freezing for Future Feasts

Slice the cooled casserole into individual portions for easy thawing and reheating. Place the slices in a single layer on a baking sheet and freeze until solid to prevent them from sticking together.

Once the portions are frozen, transfer them to a freezer-safe airtight container or a resealable plastic bag, separating layers with parchment paper. Your frozen egg casserole will retain its quality for up to 3 months.

Reheating to Perfection

When you’re ready to dive back into your delicious egg casserole, reheating is a breeze. If refrigerated, simply microwave a slice for 1-2 minutes until heated through, or warm it in a preheated oven at 175ºC (350ºF) for 15-20 minutes.

For frozen portions, let them thaw overnight in the refrigerator for best results, then follow the above reheating instructions. If you’re in a hurry, you can microwave a frozen slice for 3-4 minutes, adjusting the time as needed for your microwave’s wattage.

What to Serve with Egg Casserole

Pairing your egg casserole can bring out the best in it.

A Sweet Side

While breakfast casserole is a hearty, savory delight, pairing it with something sweet can create a beautifully balanced meal.

Try offering a fresh fruit salad, made with a vibrant mix of seasonal fruits. A drizzle of honey or a sprinkle of cinnamon over the fruit can elevate this simple side, providing a refreshing and sweet contrast to the rich, savory casserole.

Alternatively, a side of homemade waffles drizzled in maple syrup can also complement the flavors wonderfully.

A Bread Basket

A basket of assorted bread can be a wonderful addition to your egg casserole meal. From air fryer toast to French bread, the options are plentiful. For a fun twist, offering flavored bread like garlic or cheese can add an extra layer of yum to your breakfast or brunch.

Beverage Pairings

No meal is complete without the perfect beverage to sip alongside it. For breakfast or brunch, serve your egg casserole with a selection of juices, like orange, apple, or a tropical mix.

If you’re catering to an adult crowd, Champagne Cocktails or Bloody Marias elevate your brunch to a whole new level.

For a non-alcoholic option that still feels special, a Margarita Mocktail or a Spicy Pineapple Mojito Mocktail can be delightful.

More Breakfast Casseroles and Recipes For You To Try

• Cheesy Hash Brown Casserole
• French Toast Casserole
• Egg Bites
• Air Fryer Egg Bites
• Air Fryer Breakfast Potatoes