Breakfast Casserole Recipe

There’s something quietly magical about a dish that lets you join the party.

While everyone else is chatting over coffee, you’re not stuck at the stove flipping pancakes.

Why This Recipe Earned a Permanent Spot

This recipe, an adaptation from my mom’s classic, solves the host’s classic morning dilemma.

It delivers incredible, hearty flavor while giving you back your time and peace of mind.

Ingredients Needed for the Recipe

Gathering these simple components is the first step toward a stress-free morning.

• Yukon Gold Potatoes: They roast into a golden, crispy foundation that holds everything together.
• Extra-Virgin Olive Oil: Used for roasting the potatoes and sautéing the veggies, it adds a subtle, fruity depth.
• Sea Salt & Black Pepper: These essentials build the layers of seasoning in every component.
• Large Eggs & Milk: Whisked together, they create the delicate, fluffy custard that binds the casserole.
• Yellow Onion & Garlic: Sautéed until soft, they form the aromatic backbone of the vegetable mix.
• Red & Green Bell Peppers: These add sweet, vibrant color and a satisfying crunch.
• Fresh Spinach: It wilts down seamlessly, offering pockets of green and a mild, earthy note.
• Green Onions: A fresh, peppery finish, used both inside the casserole and as a garnish on top.
• Shredded Cheddar Cheese: Melty, rich, and salty, it provides pockets of gooey comfort in every bite.

How to make Breakfast Casserole?

The process is a satisfying layering of textures and flavors, each step simple and clear.

Step 1 – Roast the Potatoes

Chop your potatoes into small, quarter-inch cubes for maximum crispness.

Toss them with oil, salt, and pepper, then roast until they’re tender and speckled with brown.

Step 2 – Whisk the Egg Base

In a large bowl, simply whisk the eggs, milk, and a portion of the salt together.

This mixture will seem loose, but it bakes up into a wonderfully light and set custard.

Step 3 – Sauté the Vegetables

Cook the onion until it’s soft and translucent, then stir in the peppers and garlic.

Finally, add the spinach and half the green onions, just until the leaves wilt beautifully.

Step 4 – Assemble the Layers

In your oiled dish, spread the roasted potatoes, then most of the cheese, followed by the veggie mix.

Gently pour the egg mixture over everything, and finish with the remaining cheese and green onions.

Step 5 – Bake and Rest

Bake until the center is perfectly set and the top is a gorgeous, golden brown.

Letting it rest for five minutes is crucial, it allows everything to settle for clean slices.

Make-Ahead Strategies That Actually Work

This is where the recipe truly shines, offering you two fantastic paths to convenience.

You can fully assemble the casserole the night before and refrigerate it, unbaked.

Or, you can prep the potatoes and veggies ahead, storing them separately for lightning-fast assembly in the morning.

Either way, you walk into your kitchen with a plan already executed.

Tips

Small adjustments can make your casserole uniquely yours, and even more foolproof.

• For extra crispy potatoes, spread them in a single, uncrowded layer on the baking sheet.
• Don’t skip the resting time after baking—it’s the secret to slices that hold their shape.
• If your skillet seems crowded when adding the spinach, simply toss it with tongs as it wilts.
• Test for doneness by gently jiggling the dish; the center should be set, not sloshy.

Creative Twists and Swaps

This recipe is a wonderfully adaptable template, eager for your personal touch.

Swap the potatoes for diced sweet potatoes or even thawed frozen hash browns for a different texture.

Try using pepper jack for a spicy kick, or a mix of mozzarella and parmesan for a mellower flavor.

Almost any vegetable works here—think sautéed mushrooms, asparagus, or zucchini.

That’s the real beauty of it, you can clean out the fridge and create something delicious.

Serving and Storing Your Masterpiece

Fresh fruit on the side is all you need for a complete, satisfying meal.

Leftovers store beautifully, tasting just as good the next day, which is a rare and wonderful trait.

Keep them refrigerated for up to three days, or wrap slices tightly to freeze for later.

Reheating is a breeze, whether you use the microwave for speed or the oven to recrisp the edges.

Honestly, knowing there’s a slice waiting for you is a lovely way to greet a quiet Tuesday.

Print Recipe

Breakfast Casserole Recipe

Author: Kelsey Perez Cooking Method: Oven Cuisine: American Courses: Breakfast

Difficulty: easy Prep Time 25 mins Cook Time 45 mins Rest Time 5 mins Total Time 1 hr 15 mins

Cooking Temp: 350  F Servings: 8 Estimated Cost: $ Medium Calories: 320

Best Season: Winter, Spring, Fall, Holiday

Description

This hearty breakfast casserole is perfect for feeding a crowd! Packed with roasted potatoes, colorful sautéed veggies, fluffy eggs, and melted cheddar cheese, it's both satisfying and simple to prepare. Best of all, it can be fully assembled the night before and baked fresh in the morning—ideal for holidays, brunches, or lazy weekends.

ingredients

Servings

For the potatoes

• 3 Yukon Gold potatoes (about 1 pound, chopped into ¼-inch pieces)
• 1 tablespoon extra-virgin olive oil
• ½ teaspoon sea salt
• Freshly ground black pepper (to taste)

For the casserole

• 12 large eggs
• 1 cup milk (any kind (whole, unsweetened almond, etc.))
• 1¼ teaspoons sea salt (divided)
• 2 tablespoons extra-virgin olive oil (plus more for greasing the dish)
• ½ medium yellow onion (chopped)
• Freshly ground black pepper (to taste)
• 2 garlic cloves (chopped)
• 1 red bell pepper (stemmed, seeded, and chopped)
• 1 green bell pepper (stemmed, seeded, and chopped)
• 1 cup fresh spinach (roughly chopped)
• 4 green onions (chopped)
• 1½ cups shredded cheddar cheese

Instructions

1. Preheat the oven to 425°F. Line a baking sheet with parchment paper.
2. Place chopped potatoes on the baking sheet. Drizzle with 1 tbsp olive oil, ½ tsp salt, and several grinds of pepper. Toss to coat and spread evenly. Roast for 20–25 minutes until tender and browned.
3. Reduce oven temperature to 350°F. Lightly oil a 9×13-inch baking dish.
4. In a large bowl, whisk together eggs, milk, and ¼ tsp salt. Set aside.
5. In a large skillet over medium heat, heat 2 tbsp olive oil. Add onion, remaining 1 tsp salt, and pepper. Cook 5–8 minutes until soft. Add garlic and bell peppers; cook 2 minutes more. Stir in spinach and half the green onions; cook until spinach wilts.
6. Spread roasted potatoes in the baking dish. Top with 1 cup cheese, then sautéed veggies. Pour egg mixture evenly over top. Sprinkle with remaining ½ cup cheese and reserved green onions.
7. Bake at 350°F for 40–45 minutes, until eggs are set and top is golden.
8. Let stand 5 minutes before slicing and serving.

Nutrition Facts

Servings 8

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Amount Per Serving

Calories 320kcal

% Daily Value *

Total Fat 18gg28%

Saturated Fat 7gg35%

Trans Fat 0gg

Cholesterol 315mgmg105%

Sodium 580mgmg25%

Potassium 420mgmg12%

Total Carbohydrate 18gg6%

Dietary Fiber 2gg8%

Sugars 4gg

Protein 20gg40%

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Calcium 20 mg

Iron 10 mg

* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.

Note

• Make ahead: Assemble the entire casserole the night before, cover tightly, and refrigerate. Bake in the morning after 15 minutes at room temperature.
• Customize veggies: Swap in mushrooms, zucchini, asparagus, or broccoli for variety.
• Dairy-free option: Use plant-based milk and omit cheese—still delicious like a veggie frittata!
• Add protein: For a non-vegetarian version, mix in cooked sausage, ham, or bacon.

Keywords: breakfast casserole, make-ahead breakfast, egg casserole, vegetarian breakfast, holiday brunch