Christmas Breakfast Casserole (Overnight Sausage, Egg and Hash Brown Bake)

This Christmas breakfast casserole is the one dish I refuse to make on Christmas morning — I make it on Christmas Eve. Browned breakfast sausage, crispy shredded hash browns, sweet peppers and a lot of sharp cheddar sit under a fluffy egg custard (there is cottage cheese blended in, which nobody can taste and everybody notices), the dish goes in the fridge overnight, and in the morning it bakes for 50 minutes while coffee happens and paper gets torn. Twelve squares, 26g of protein each, and it is the same make-ahead logic that runs my breakfast egg muffins and freezer breakfast sandwiches the rest of the year. If you are planning a high protein, GLP-1 friendly holiday table, this is the breakfast on it. For the ordinary weekday mornings between the holidays, the freshly updated high protein overnight oats are my 32g-protein, five-minute answer.

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Why this is the breakfast casserole that survives Christmas morning.

• It is built the night before, on purpose. An overnight rest is not a shortcut here — it is the point. The hash browns soak up the custard and crisp underneath instead of floating, the sausage flavors the eggs, and the whole thing bakes more evenly from cold. On Christmas morning you turn on the oven and do nothing else.
• The sausage and the potatoes are browned first. Raw sausage dumped into egg steams gray and leaks fat into the custard. Browning it hard with the onion and peppers (the same hands-off trick as my ground turkey sweet potato skillet) gives you crispy bits and a drier, cleaner bake. The hash browns go in thawed and pressed flat so they turn into a crust, not mush.
• A little cottage cheese keeps the eggs tender and pushes the protein up. Blended into the custard, cottage cheese adds creaminess without the heavy cream and lifts every square to 26g protein — the same reason it is in my cottage cheese egg bites. Run the numbers for your own crowd in the protein calculator.

Here's what you'll need.

Breakfast sausage, frozen shredded hash browns (thawed), a dozen eggs, milk, cottage cheese, sharp cheddar, an onion, a red bell pepper, chives, salt, pepper and a pinch of smoked paprika — nothing you need a special trip for in December.

Here's how it all comes together.

STEP 1 — Brown the sausage, onion and pepper.

Cook the breakfast sausage in a large skillet over medium-high heat, breaking it up, until deeply browned — about 7 minutes. Add the onion and red pepper and cook 3 more minutes until soft. Tip the whole pan into a strainer so the fat drains off; wet sausage is what makes a casserole greasy.

STEP 2 — Press the hash browns into the dish.

Butter a 9x13 baking dish. Squeeze the thawed hash browns in a clean towel to get rid of the water, then press them into an even layer across the bottom and season with salt, pepper and the smoked paprika. This layer bakes into a crisp potato crust under everything else.

STEP 3 — Whisk the custard.

Whisk the eggs, milk, cottage cheese, 1 teaspoon salt and plenty of black pepper until smooth and a little frothy — about a minute. If you want it perfectly silky, give the cottage cheese and milk 10 seconds in a blender first, then whisk in the eggs.

STEP 4 — Layer and pour.

Scatter the drained sausage mixture over the hash browns, then two-thirds of the cheddar. Pour the egg custard slowly over everything so it seeps into the corners, then top with the rest of the cheese and the chives.

STEP 5 — Cover and chill overnight.

Cover tightly with foil and refrigerate at least 8 hours or up to 24. This is the make-ahead step that makes Christmas morning easy — the potatoes drink up the custard and the whole thing sets up so it bakes evenly from cold.

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Things I learned while testing this recipe.

• Squeeze the hash browns dry. Thawed hash browns hold a shocking amount of water. My first test skipped the towel and the bottom layer was soft and gray; squeezed hard, it bakes into a crisp golden crust. Fresh grated potato works the same way — squeeze until nothing drips.
• Do not skip the drain after browning. Breakfast sausage renders a lot of fat. If it goes into the dish, it pools on top of the custard and the eggs taste greasy. Thirty seconds in a strainer fixes it completely.
• Bake it from the fridge, not the counter. A cold casserole bakes more evenly than one that sat out for an hour, because the custard sets slowly from the edges in. Cold-to-oven just needs the covered 25 minutes first so the top does not brown before the middle sets.
• A knife test beats a timer. Ovens and dishes vary. The casserole is done when a knife in the center comes out clean and the middle no longer jiggles when you nudge the dish. If the top is browning early, lay the foil back on loosely.

Your Christmas morning timeline (and why this works for a GLP-1 friendly table).

• December 23: shop and brown the sausage. The sausage, onion and pepper mixture keeps 2 days in the fridge, so you can do the only real cooking two days early. Shred the cheese now too.
• Christmas Eve, after dinner: assemble, cover, chill. Fifteen minutes of layering and pouring, then the fridge does the work. Set the baking dish on a sheet pan so it slides straight into the oven in the morning.
• Christmas morning: oven on at 8, breakfast at 9. Preheat, bake covered 25 minutes, uncovered 25 to 30, rest 10. A square is about 290 calories with 26g protein and 4g fiber — a breakfast that holds people until the big meal instead of a sugar crash by 11. Serve it with a cold cucumber salad or fruit and it is a complete, GLP-1 friendly plate.

Here's what I'd serve with this.

• Cinnamon apple cake — the sweet thing on the Christmas brunch table
• Blueberry cottage cheese breakfast bake — a second make-ahead dish for a bigger crowd
• Pumpkin bread — bake it the day before and slice it at the table
• Air fryer smashed potatoes — if you want a crisp potato side instead of more hash browns
• Greek yogurt banana bread — the loaf that disappears first

Just in case you have leftovers.

Storing: Cool completely, then keep covered in the fridge for up to 4 days. For the freezer, cut into squares, wrap each in foil, and freeze up to 2 months — the hash brown base holds up better than most egg bakes.

Reheating: Microwave a square for 90 seconds to 2 minutes, or warm the whole dish covered at 325°F for 20 to 25 minutes. From frozen, bake wrapped squares at 350°F for 30 minutes, or thaw overnight and microwave.

More easy holiday breakfast recipes...

Cottage cheese breakfast casserole Breakfast egg muffins Freezer breakfast sandwiches Apple cinnamon baked oatmeal

This is the first of my Christmas and holiday recipes for this year. If you are feeding a crowd the rest of the week, the crockpot turkey breast, green bean casserole from scratch and homemade stuffing are the make-ahead dishes I lean on for Thanksgiving and again at Christmas, and the air fryer salmon bites (freshly updated today) are my 15-minute answer for the nights in between.

More high protein breakfasts that feed a crowd

If a make-ahead, 26g-protein breakfast that keeps everyone full through the morning is how you want the holidays to go, the Ultimate GLP-1 High Protein High Fiber Cookbook is full of exactly these — egg bakes, casseroles and meal-prep breakfasts that repeat well.

Get the cookbook on Amazon

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