Cheesy Potato Breakfast Casserole

This cheesy potato breakfast casserole transforms ordinary morning ingredients into a comforting, flavor-packed meal that's perfect for lazy weekends or special brunches. The combination of crispy-edged hash browns, savory sausage, and colorful vegetables creates a hearty base, while the egg mixture binds everything together beneath a glorious blanket of melted cheese. It's a versatile dish that allows for endless customization while maintaining that soul-satisfying quality that makes breakfast casseroles so beloved.

I discovered this recipe years ago when hosting a holiday brunch for my extended family. Everyone was still in pajamas, coffee was brewing, and I needed something substantial that didn't require me to stand at the stove flipping pancakes. The casserole was such a hit that my brother-in-law, who typically skips breakfast altogether, asked for the recipe! Now it's my signature dish for any morning gathering.

Ingredients You'll Need

• 4 cups Frozen Hash Browns, thawed: These create the perfect potato base without the work of shredding potatoes yourself. Look for ones without added seasonings for better flavor control.
• 1 pound Breakfast Sausage: Provides savory depth and protein. Choose mild or spicy depending on your preference, or substitute turkey sausage for a lighter option.
• 1 medium Onion, diced: Adds aromatic sweetness that permeates the entire dish. Yellow onions work best for their balanced flavor when cooked.
• 1 Bell Pepper, diced: Brings color, freshness, and subtle sweetness. Red peppers offer the most natural sweetness, but any color works beautifully.
• 8 large Eggs: Acts as the binding agent that holds everything together. Farm-fresh eggs with bright orange yolks will give your casserole a lovely color.
• 1 cup Whole Milk: Creates richness and a custardy texture. The fat content is important here for the best texture.
• 1/2 cup Sour Cream or Cottage Cheese: Adds tanginess and creaminess. Cottage cheese provides extra protein if that's important to you.
• 1 tablespoon Dijon Mustard: This secret ingredient brightens all the flavors without tasting mustardy.
• 1 teaspoon each Garlic Powder and Onion Powder: Provides depth of flavor without the work of mincing fresh garlic.
• 1/2 teaspoon Smoked Paprika: Adds a subtle smokiness that makes people wonder what makes this casserole so special.
• Salt and Pepper to taste: Essential for bringing all flavors together.
• 1 1/2 cups Sharp Cheddar Cheese, shredded: Offers that classic tangy cheese flavor. Freshly grated melts much better than pre-shredded.
• 1 cup Monterey Jack Cheese, shredded: Provides amazing meltability and a milder flavor that complements the sharp cheddar.

Pin it

Step-by-Step Cooking Instructions

Prepare Your Baking Dish:

Preheat your oven to 375°F (190°C) to ensure it reaches the proper temperature before baking. While it's heating, take a moment to thoroughly grease a 9×13-inch baking dish with cooking spray or butter, making sure to cover the sides as well as the bottom. This prevents sticking and makes serving much easier, especially when you're trying to get those perfect squares out of the dish for presentation.

Create Your Flavor Base:

Heat a large skillet over medium-high heat until it's hot enough that a drop of water sizzles on contact. Add the breakfast sausage, breaking it into crumbles with a wooden spoon as it begins to brown. When the sausage is about halfway cooked, add the diced onion and bell peppers to the pan. This timing allows the vegetables to soften perfectly without becoming mushy, while also absorbing the savory flavors from the meat. Continue cooking until the sausage is completely browned and the vegetables have softened slightly, about 5-8 minutes total.

Build The Casserole Foundation:

Remove the skillet from heat and allow the mixture to cool slightly, about 2-3 minutes. This prevents the hash browns from starting to cook unevenly. Add the thawed hash browns to the sausage mixture, using a large spoon to gently fold everything together until well combined. The residual heat will warm the potatoes without cooking them. Carefully transfer this mixture to your prepared baking dish, spreading it evenly with the back of a spoon to create a level base for your egg mixture.

Create The Egg Mixture:

In a large bowl, crack all 8 eggs and whisk them until the whites and yolks are fully incorporated. Add the milk, sour cream (or cottage cheese), Dijon mustard, garlic powder, onion powder, smoked paprika, salt, and pepper. Whisk vigorously until the mixture is smooth with no streaks of egg white or clumps of spice. The sour cream may take a little extra effort to incorporate completely. Once smooth, stir in 1 cup of the shredded cheddar cheese and all of the Monterey Jack cheese, reserving the remaining 1/2 cup of cheddar for topping.

Combine Everything Together:

Pour the egg and cheese mixture slowly and evenly over the hash brown base in the baking dish. Use a fork to gently press down on the potato mixture if needed, helping the egg mixture to penetrate throughout the casserole rather than sitting on top. The liquid should seep down through the layers, ensuring every bite will be moist and flavorful after baking.

Bake To Perfection:

Place the baking dish on the middle rack of your preheated oven and bake uncovered for 35-40 minutes. You'll know it's nearing completion when the edges begin to turn golden brown and pull away slightly from the sides of the dish. The center should be mostly set but might still have a slight jiggle. At this point, sprinkle the remaining 1/2 cup of cheddar cheese evenly over the top and return to the oven for an additional 5-10 minutes until the cheese is completely melted, bubbling, and beginning to develop those irresistible golden spots.

Rest Before Serving:

Once done, remove the casserole from the oven and place it on a heat-safe surface. Allow it to rest for 5-10 minutes before cutting into it. This crucial step allows the eggs to fully set and makes for cleaner, more picture-perfect servings. During this time, prepare any optional toppings like sliced green onions, diced avocado, or a side of salsa. Serve while still warm for the best flavor and texture experience.

My family has a running joke about my obsession with properly thawed hash browns. Years ago, I rushed this step and ended up with a watery casserole that earned me endless teasing. Now I always thaw them overnight in the refrigerator, then spread them on a clean kitchen towel and press gently to remove any remaining moisture. This extra five minutes of prep makes all the difference between a good breakfast casserole and a great one that people remember.

Perfect Pairings

While this casserole is certainly substantial enough to stand alone, a few thoughtfully chosen sides can transform it into a memorable brunch spread. Fresh fruit offers a welcome contrast to the savory richness - try a simple berry medley or citrus segments. For a special occasion, consider adding a light salad with vinaigrette dressing or warm, flaky biscuits with honey butter. Coffee is the traditional beverage pairing, but a spicy Bloody Mary or mimosa turns breakfast into a celebration.

Creative Variations

The beauty of this recipe lies in its adaptability. For a Southwestern twist, add a can of diced green chiles and substitute pepper jack cheese for the Monterey Jack. Mediterranean flavors work beautifully too - try adding spinach, feta, and diced tomatoes. Vegetarians can skip the sausage altogether and double up on vegetables like mushrooms, which provide a satisfying umami quality. For those following a lower-carb lifestyle, cauliflower rice can replace some or all of the hash browns.

Make-Ahead Instructions

This casserole was designed with convenience in mind. Assemble everything up to 24 hours in advance, cover tightly with plastic wrap, and refrigerate. When you're ready to bake, remove it from the refrigerator about 30 minutes beforehand to take the chill off, then add about 10-15 minutes to the baking time. You can also freeze the unbaked casserole for up to one month - just thaw completely in the refrigerator before baking.

Pin it

Troubleshooting Tips

If your casserole seems too wet in the center, continue baking in five-minute increments until a knife inserted in the center comes out clean. Conversely, if it's browning too quickly on top but still uncooked in the middle, cover loosely with aluminum foil for the remainder of the baking time. Remember that every oven has slight temperature variations, so visual cues are often more reliable than strict timing.

I've been making this casserole for nearly a decade now, and it never fails to impress. What I love most is how it brings people together around the table in their pajamas, coffee mugs in hand, ready to start the day on a delicious note. There's something magical about the aroma that fills the house as it bakes – it seems to draw everyone to the kitchen like a magnet. Even my teenager, who typically sleeps until noon on weekends, has been known to appear mysteriously right as this casserole comes out of the oven. It's become our special weekend tradition, one that I hope will continue for generations to come.

Recipe Tips & Questions

→ Can I prepare this casserole the night before?

Yes, this casserole is perfect for making ahead. Prepare everything up to the baking step, cover tightly with plastic wrap or foil, and refrigerate overnight. When ready to bake, remove from the refrigerator while preheating the oven, then bake as directed, adding about 5-10 extra minutes to the cooking time.

→ Can I use fresh potatoes instead of frozen hash browns?

Yes, you can substitute fresh potatoes. Peel and grate about 2 pounds of russet potatoes, then rinse well under cold water and pat completely dry with paper towels to remove excess starch. This step is important to prevent soggy results.

→ What other meats can I use besides breakfast sausage?

This recipe is very versatile. You can substitute the breakfast sausage with cooked and crumbled bacon, diced ham, chorizo, or even ground beef or turkey. For a vegetarian option, you can use plant-based meat alternatives or simply add more vegetables.

→ How do I know when the casserole is fully cooked?

The casserole is done when the center is set and no longer jiggly, and a knife inserted in the center comes out clean. The internal temperature should reach 160°F, and the top should be golden brown with melted, bubbly cheese.

→ How should I store and reheat leftovers?

Store leftovers in an airtight container in the refrigerator for up to 4 days. Reheat individual portions in the microwave for 1-2 minutes or until heated through. For larger portions, cover with foil and reheat in a 350°F oven for 15-20 minutes.