Savory Veggie Breakfast Casserole

This savory veggie breakfast casserole is an easy way to turn eggs, potatoes, and colorful vegetables into a warm breakfast that can feed several people—or keep one person out of the kitchen for several mornings.

Golden potatoes give it some staying power, while mushrooms, peppers, spinach, onion, and garlic bring plenty of flavor and color. Everything is held together with a simple seasoned egg mixture and baked until set and lightly golden.

Best of all, most of the work happens once. Tomorrow morning, breakfast is already sitting in the refrigerator waiting for you. That’s the kind of employee I appreciate. 😂

Why You’ll Love This Savory Veggie Breakfast Casserole

• Great for meal prep: Bake once and portion breakfast for several mornings.
• Loaded with vegetables: Peppers, mushrooms, spinach and onion add flavor and color.
• Simple ingredients: Nothing here requires a specialty-store expedition.
• Easy to customize: Change the vegetables or seasonings based on what you have.
• Good for sharing: One casserole can handle a family breakfast or weekend brunch.

Ingredients

• 1 tablespoon extra virgin olive oil, divided
• 2 cups Yukon Gold potatoes, cut into small ½-inch cubes
• 1 cup sliced cremini mushrooms
• ½ cup diced red bell pepper
• ½ cup diced green bell pepper
• ½ cup diced onion
• 2 cloves garlic, minced
• 2 cups fresh baby spinach
• 8 large eggs
• ½ cup unsweetened plant milk
• 2 tablespoons nutritional yeast
• ½ teaspoon smoked paprika
• ½ teaspoon dried thyme
• ½ teaspoon salt
• ¼ teaspoon cracked black pepper
• 2 tablespoons finely chopped fresh parsley

Instructions

1. Preheat the oven to 375°F (190°C). Lightly grease an 8-by-8-inch baking dish.
2. Heat half the olive oil in a large skillet over medium heat. Add the diced potatoes and cook for about 8–10 minutes, stirring occasionally, until they begin to soften and develop lightly golden edges.
3. Add the remaining olive oil, mushrooms, bell peppers, and onion. Cook for another 5–6 minutes, until the vegetables begin to soften and the mushrooms release most of their moisture.
4. Stir in the garlic and spinach. Cook for 1–2 minutes, just until the spinach wilts. Remove the skillet from the heat.
5. In a large bowl, whisk together the eggs, plant milk, nutritional yeast, smoked paprika, thyme, salt, and black pepper.
6. Spread the cooked vegetable mixture evenly in the prepared baking dish.
7. Pour the egg mixture evenly over the vegetables. Gently move the vegetables with a spoon if needed so the egg mixture settles throughout the casserole.
8. Bake for 25–30 minutes, or until the center is set and the top is lightly golden.
9. Let the casserole rest for 5–10 minutes before slicing.
10. Sprinkle with fresh parsley and serve warm.

Yum’s Tips for Savory Veggie Breakfast Casserole

Cut the potatoes small. Keeping them around ½ inch helps them cook through before they go into the casserole.

Cook the vegetables first. Mushrooms, spinach, and other vegetables contain plenty of water. Cooking them before baking helps prevent a watery casserole.

Don’t overbake it. Once the center is set, it’s ready. Leaving an egg casserole in the oven too long can make it dry and rubbery.

Give it a few minutes before slicing. That short rest helps the casserole hold together when you cut it.

Breakfast Casserole Variations

Change the vegetables: Broccoli, zucchini, asparagus, or kale can work well. Just cook vegetables with significant moisture before adding them.

Add a little heat: Add crushed red pepper or a pinch of cayenne.

Change the herbs: Try basil, oregano, rosemary, or an Italian seasoning blend.

Add beans: A small amount of drained and rinsed white beans can make the casserole even heartier.

Skip the potatoes: Leave them out for a lighter vegetable-and-egg casserole, or replace them with cooked sweet potato.

Storage & Meal Prep

Allow the casserole to cool before transferring leftovers to an airtight container. Refrigerate for up to 4 days.

Individual portions of savory veggie breakfast casserole make meal prep especially easy. Store them separately so you can grab one portion without disturbing the rest of the casserole.

Reheat individual pieces in the microwave until heated through, or warm them gently in a covered skillet.

The vegetables can also be cooked the night before and refrigerated. In the morning, whisk the egg mixture, assemble the casserole, and bake.

Nutrition Highlights

Eggs provide protein, while potatoes contribute carbohydrates and potassium. The assortment of peppers, mushrooms, spinach, and onions adds fiber and a variety of vitamins and minerals.

Using several vegetables also adds plenty of flavor and texture without requiring a complicated ingredient list.

Perfect Pairings

Fresh fruit makes an easy contrast to the warm savory casserole. Try berries, orange slices, melon, or sliced apples.

Whole-grain toast works well when you want a more substantial breakfast, while sliced avocado adds a creamy element.

Coffee or tea keeps things simple for an everyday breakfast, and this casserole also fits naturally into a larger weekend brunch.

Yum’s Note

A breakfast casserole is one of those recipes that makes tomorrow morning feel a little more organized than it actually is. 😂 I especially like that you can use the basic formula and change the vegetables depending on what’s already waiting in the refrigerator.

If you enjoy warm savory breakfasts, try Yum’s Mediterranean Breakfast Skillet next. And if you’d like more simple recipes and practical ideas from Yum, Join Yum’s Kitchen.

If you make this Savory Veggie Breakfast Casserole, leave a comment and tell me which vegetables you used, and share the recipe with someone who could use breakfast already waiting for them.