This fluffy Oven-Baked Western Omelet Casserole is the easiest way to make a Western omelet. It's the ideal make-ahead breakfast casserole with eggs, tender ham, bell peppers, and mushrooms. This family favorite is perfect for busy mornings!
You can even assemble it the night before and bake it first thing in the morning, making it perfect for Christmas breakfast or holiday brunch.
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This breakfast egg casserole is an EASY recipe that can be made ahead of time and refrigerated, just like this Eggs Benedict Casserole with Hollandaise Sauce or this Bisquick Breakfast Casserole.
And there's no standing at the stove cooking a traditional omelet like my Spinach Mushroom Omelette With Feta Cheese.
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Why You'll Love This Recipe
- You can make this Southwestern omelet ahead of time and store it in the fridge.
- It only needs 15 minutes of prep time.
- It's high in protein and low in carbs.
- This healthy breakfast casserole can be served for breakfast, brunch, a light lunch, or dinner.
- Great for meal prep.
- It can be scaled easily for a larger or smaller group.
Recipe Ingredients
Make this Western omelette using simple ingredients from your local grocery store.
Ingredient Notes:
- Eggs. I used large eggs, including the egg yolks.
- Milk. I used 1% milk, but you can use almond milk, coconut milk, or oat milk.
- Shredded cheese. I used white cheddar cheese, but you can use your favorite kind. It would be great with sharp cheddar cheese, gouda, swiss, mozzarella, or even feta.
- Diced ham. Ham goes great in an omelet; just make sure it is already pre-cooked. You can use leftover Baked Ham or leftover Double Smoked Ham. You could also use Air Fryer Bacon, thinly sliced Smoked Steak, Air Fryer Sausage, Smoked Sausage, leftover chicken from Air Fryer Chicken Thighs, Air Fryer Chicken Breasts, Instant Pot Chicken Breasts, Smoked Chicken Breasts or Smoked Chicken Thighs, or even Pellet Smoked Salmon.
- Mushrooms and bell peppers: I used orange peppers, but you could also use a green bell pepper or a red bell pepper. You can also use spinach, tomatoes, and leeks. Look in your fridge and use up anything sitting in the crisper.
See the printable recipe card for exact measurements and a complete list of ingredients.
How To Make Oven-Baked Western Omelet Casserole
Step-By-Step Instructions
Step 1: Preheat your oven to 350 degrees F. Use a whisk or hand mixer to beat eggs in a large mixing bowl.
Step 2: Add milk, seasoning salt, and black pepper to the fluffy eggs. Whisk to combine.
Step 3: Add the diced ham and shredded cheddar cheese.
Step 4: Add the bell peppers and mushrooms. Stir to combine.
Step 5: Pour the egg mixture into a greased 9 x 12 baking dish or large skillet.
Step 6: Bake for 45 minutes in the preheated oven until the top is golden brown and the eggs are set. Cut the casserole into squares and serve immediately.
Variations
This baked Denver omelet casserole is easy to modify to suit your tastes.
- Are you a vegetarian? Leave out the meat.
- Do you want to make it healthier? Add more vegetables.
- Add red pepper flakes or a can of green chilies to spice it up.
- Add more seasoning, such as garlic powder or onion powder.
- The sky is the limit for what you can do with this baked oven omelet.
- Are you out camping? Cook it in a cast iron skillet!
Serving Suggestions
Serve this Western baked omelet with:
- Hot sauce or ketchup.
- Top with your favorite toppings, such as sour cream, avocado, sliced tomatoes, or fresh fruit.
- Air Fryer Crispy Breakfast Potatoes or Crispy Oven-Roasted Potatoes
- Fruit Salad With Cool Whip or Watermelon Basil Salad with Feta
- Air Fryer Toast, English muffin, or a loaf of crusty No Knead Sourdough Bread.
- Put it inside a wrap for an easy breakfast.
Expert Tips
- Whisk the eggs well to ensure they are fully combined and aerated to create a light and fluffy texture.
- Let the omelet rest for a few minutes before serving to help it set.
- Add spinach, tomatoes, onions, or your favorite veggies for extra flavor and nutrition.
- Don't overcook the omelet. It should be slightly firm to the touch but still moist and tender.
- If using vegetables that release moisture, such as fresh mushrooms or tomatoes, sauté them in a separate pan before adding them to the egg mixture to prevent the omelet from becoming watery.
- Store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, microwave on high for 30 seconds to 1 minute or until heated through.
What else can you put in this easy breakfast casserole?
- Crisp bacon or sausage.
- Diced tomatoes, cherry tomatoes, or a medium onion.
- Leeks, celery, green onions, or garlic
- Fresh herbs, spinach, or zucchini
FAQs
Yes, you can substitute whole eggs with egg whites if you want a lower-calorie option. Just be aware that the texture may be slightly different.
Yes, you can make this omelet casserole ahead of time, cover it with plastic wrap, and store it in the fridge. Reheat it in the oven or microwave before serving.
The omelet is cooked when it is puffed up, golden brown and a toothpick inserted in the center comes out clean. This should take about 45 minutes in the oven.
Yes, you can adjust the seasoning to your liking. You can add more salt, pepper, or other spices.
If you like this Fluffy Oven-Baked Omelette Casserole, please take a moment to leave a star rating 🌟🌟🌟🌟🌟 and share it on social media!
Printable Recipe
Easy Fluffy Oven-Baked Omelet Casserole Recipe
Ingredients
- 12 large eggs
- 1½ cups milk
- ¾ teaspoon seasoning salt
- ¼ teaspoon black pepper
- 1½ cup diced ham
- 1 cup shredded cheddar cheese
- 1½ cup finely chopped bell peppers
- 1 cup canned mushrooms drained
Instructions
- Preheat oven to 350℉.
- Whisk together 12 eggs in a large bowl.
- Add 1½ cups milk, ¾ teaspoon seasoning salt, and ¼ teaspoon black pepper. Whisk to combine.
- Stir in 1½ cups diced ham, 1 cup shredded cheddar cheese, 1½ cups diced bell peppers, and 1 cup of canned mushrooms. Stir to combine.
- Pour the mixture into a greased 9 x 12 baking dish.
- Bake at 350℉ for 45 minutes until golden brown on top and eggs are set.
- Cut the casserole into squares and serve.
- If you loved this recipe, please leave a 5-star rating and review below!
Video
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Notes
- Whisk the eggs well to ensure they are fully combined and aerated to create a light and fluffy texture.
- Let the omelet rest for a few minutes before serving to help it set.
- Add spinach, tomatoes, or onions to give it extra flavor.
- Don't overcook the omelet. It should be slightly firm to the touch but still moist and tender.
- If using vegetables that release moisture, such as fresh mushrooms or tomatoes, sauté them in a separate pan before adding them to the egg mixture to prevent the omelet from becoming watery.
- Store leftovers in an airtight container in the refrigerator for up to 3 days. To reheat, microwave on high for 30 seconds to 1 minute or until heated through.
Nutrition
The provided nutrition information is automatically calculated. Accuracy is not guaranteed.
Did you love this recipe?
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Homeland says
The idea of assembling it the night before really sells this for me—no morning scramble, just bake and enjoy. That small shift turns a holiday brunch from stressful to actually relaxing.
J.E. Kallenbach says
Very easy and VERY GOOD!!
Lynn says
I've made this a few times now and always comes out perfectly. I use red, orange and green bell peppers, and top with green onions. I stir halfway through, and cook it at 355 since my oven seems to take longer to cook this. Thank you for the awesome recipe!!
Jeri Walker says
I'm so glad you like this recipe, Lynn! Thank you for sharing your tips, and thank you for coming back to rate the recipe and leaving a comment! I appreciate it! 🙂
Brenda says
WONDERFUL!!! I served to weekend company (2 people that we had only met) and they couldn’t stop raving about this!!!
Thank you for sharing!
Jeri says
Thank you for trying our oven baked omelet casserole, Brenda. I'm so glad you and your guests enjoyed it! It's one of our favorites! Thanks for taking the time to come back and leave a comment! 🙂
Mihaela | https://theworldisanoyster.com/ says
I used to make oven-baked omelettes (when I had more time at hand, LOL), and spinach and courgettes were always among the ingredients. Broccoli too, since my fussy eater likes it, paradoxically:) You just reminded me how nicely they turn up!
Jean says
when I first saw the photo I knew it already looks delicious and can be served on occasions too!
Nora says
Yum! This looks so delicious! Can't wait to try it out and have a bite! Thank you for sharing!
Freya says
How delicious and cheesy this looks! And so easy too!
Kay says
A great recipe that even my fussy eater daughter enjoyed! Is now a weekly meal in our house.
Amy says
This was such a great idea and honestly, so much easier, especially when I'm feeding quite a few people. I especially loved it because it enabled me to get rid of some of the vegetables that were in the fridge. They were fluffy as you said and you're right, high in protein and low in carbs is such an added bonus.
Linda says
This omelet casserole is delicious! So flavorful and easy to prep and clean up.