Introduction

This Vegetarian Hash Brown Breakfast Casserole is a hearty and flavorful way to start your day. It combines crispy hash browns with sautéed vegetables, eggs, and melted cheese for a dish that’s both comforting and satisfying. Perfect for a weekend brunch or meal prep, it’s easy to make and always a crowd-pleaser.

A rectangular baked dish with a golden yellow top layer of melted cheese mixed with dark green spinach leaves and small pieces of red bell pepper, all baked into a slightly browned and bubbly crust. The dish rests in a white baking pan with rounded handles on a white marbled surface, next to a gray and white striped cloth. Two silver forks lie to the right side of the pan, and there is a small white bowl filled with chopped green onions above the pan, along with two fresh spinach leaves on the marbled surface. Photo taken with an iphone --ar 4:5 --v 7

Ingredients

1 (20 oz) bag frozen shredded hash browns, about 4-5 cups
3 teaspoons olive or avocado oil, divided
1 cup yellow onion, chopped
2 cloves garlic, minced
1 red bell pepper, chopped
1 (8 oz) package mushrooms, chopped
1 (5 oz) bag baby spinach
1 teaspoon salt, plus more to taste
½ teaspoon ground black pepper, plus more to taste
10 eggs
½ cup non-dairy milk (unsweetened almond milk recommended)
1 ½ cups shredded sharp cheddar cheese

Instructions

Step 1: Preheat your oven to 400°F and spray a 9×13-inch baking dish with cooking spray.
Step 2: Spread the frozen shredded hash browns evenly in the baking dish. Drizzle with 1 teaspoon of oil and sprinkle with a dash of salt and pepper. Bake for about 30 minutes until the potatoes begin to brown and crisp. Press down with a spatula to help form a crust once removed from the oven.
Step 3: While the hash browns bake, heat 2 teaspoons oil in a large skillet over medium-high heat. Add chopped onion, garlic, red bell pepper, and mushrooms. Cook, stirring occasionally, until onions are translucent and mushroom liquid evaporates, about 7-10 minutes.
Step 4: Add baby spinach, salt, and pepper to the skillet. Stir until the spinach wilts, then remove from heat and set aside to cool slightly.
Step 5: In a large bowl, whisk together the eggs and non-dairy milk until well combined.
Step 6: Once the vegetables have cooled, stir them into the egg mixture along with 1 cup of the shredded cheddar cheese.
Step 7: Pour the egg and vegetable mixture over the baked hash browns in the dish. Sprinkle the remaining ½ cup of cheese evenly on top.
Step 8: Bake the casserole for 20-25 minutes, or until the eggs are fully set and no longer jiggly in the center.
Step 9: Let the casserole rest for 5 minutes before slicing and serving.

Tips & Variations

Use any combination of your favorite vegetables, such as zucchini or kale, for a different flavor and texture.
Swap sharp cheddar for a dairy-free cheese to keep this recipe fully vegan-friendly.
Press down firmly on the hash browns after baking to create a sturdier crust that holds the casserole together.
For added spice, sprinkle red pepper flakes into the vegetable mixture while cooking.

Storage

Store any leftover casserole covered in the refrigerator for up to 3 days. Reheat individual portions in the microwave until warmed through or in the oven at 350°F for about 10 minutes to maintain crispness. This casserole can also be frozen; wrap tightly and freeze for up to 1 month. Thaw overnight in the refrigerator before reheating.

How to Serve

A white rectangular baking dish holds a freshly baked egg casserole with a golden yellow top layer, speckled with green spinach leaves and small red bell pepper pieces throughout. The edges are slightly browned, showing a crispy texture. The casserole surface is uneven with visible bits of mushroom and cheese melted into the mix. The dish rests on a white marbled surface with a striped gray and white cloth underneath it, and a small white bowl filled with chopped green onions is placed nearby. Two silver forks with decorative handles are positioned to the right of the baking dish. Photo taken with an iphone --ar 4:5 --v 7

Serve this delicious recipe with your favorite sides.

FAQs

Can I use fresh potatoes instead of frozen hash browns?

Yes, but make sure to shred and cook them well beforehand to avoid excess moisture. Par-cook them in a skillet or oven to achieve a crispy texture before assembling the casserole.

Is this casserole suitable for vegan diets?

This recipe uses eggs and cheese, so it is not vegan as written. To make it vegan, substitute eggs with a chickpea flour batter or a commercial egg replacer, and use a dairy-free cheese alternative.