Can I make this Christmas breakfast casserole ahead of time?

Yes. Assemble the casserole up to the point of baking, cover tightly, and refrigerate for up to 24 hours. For best results, remove from fridge 20–30 minutes before baking so it warms slightly. To freeze, wrap the unbaked casserole well and store 2–3 months; thaw overnight in the refrigerator before baking. If you bake from chilled, add about 10–15 minutes to the bake time; if baking from fully frozen, plan for 60–75 minutes at 350°F and use a thermometer to check doneness.

How long will leftover Christmas breakfast casserole keep and how should I reheat it?

Store leftovers in an airtight container in the refrigerator for 3–4 days. Freeze individual portions for 2–3 months. Reheat slices in the oven at 350°F for 12–18 minutes (covered the first few minutes to retain moisture) or use a microwave in 60–90 second bursts until hot. When reheating, heat to at least 165°F for safety. Label frozen portions with date and reheating times for quick reference.

Can I make a gluten-free, dairy-free, or vegetarian Christmas breakfast casserole?

Yes. For gluten-free, swap regular bread for certified gluten-free bread or use cooked gluten-free grains. For dairy-free, use unsweetened oat or soy milk and a dairy-free shredded cheese. To make it vegetarian, omit sausage or bacon and add cooked mushrooms, spinach, roasted peppers, or a plant-based sausage. Keep ratios similar: 6–8 cups bread, 6–8 eggs, 2–3 cups milk (dairy or plant), 3 cups cheese or substitute. Test a small batch first to confirm texture and seasoning.

Can I make this casserole in muffin tins or freeze single-serving portions for grab-and-go breakfasts?

Yes. Use a greased 12- or 15-cup muffin tin, fill each cup about 3/4 full, and bake at 350°F for 18–25 minutes until set. A 9x13 usually yields about 12–15 muffins. To freeze single servings, cool completely, wrap tightly in plastic and foil, and freeze up to 2–3 months. Reheat frozen muffins in a 350°F oven for 18–25 minutes or microwave 60–90 seconds. Label portions with contents and date for easy morning retrieval.

What food-safety tips and internal temperature should I follow when making a Christmas breakfast casserole?

Follow these basics: refrigerate ingredients promptly (do not leave perishable food at room temperature over 2 hours), use pre-cooked meats or fully cook raw meats before adding, and bake until the casserole reaches an internal temperature of 160°F for egg-based dishes. Cool leftovers quickly and refrigerate within two hours. Use a digital instant-read thermometer inserted into the center to confirm doneness and safety. For more tips, link to your holiday food-safety or thermometer guide.

Christmas Breakfast Casserole Make Ahead For Busy Mornings

Name: Christmas Breakfast Casserole
Prep time: 15 min
Cook time: 50 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: – 2 pounds sausage adds savory protein and rich flavor base; – 12 eggs binds everything and provides high-quality protein; – 1 cup sour cream (light or regular) creates creamy custardy texture; – 1/4 cup milk thins the mixture for smooth consistency; – 1 teaspoon salt enhances overall taste; – 1/2 teaspoon ground black pepper adds mild heat and balance; – 4 green onions, chopped brings fresh, mild onion flavor and color; – 1/2 green bell pepper, diced offers crunch and vitamin C; – 1/2 red bell pepper, diced provides sweetness and vibrant hue; – 2 cups shredded cheddar cheese melts for gooey richness

Ingredients

– 2 pounds sausage adds savory protein and rich flavor base

– 12 eggs binds everything and provides high-quality protein

– 1 cup sour cream (light or regular) creates creamy custardy texture

– 1/4 cup milk thins the mixture for smooth consistency

– 1 teaspoon salt enhances overall taste

– 1/2 teaspoon ground black pepper adds mild heat and balance

– 4 green onions, chopped brings fresh, mild onion flavor and color

– 1/2 green bell pepper, diced offers crunch and vitamin C

– 1/2 red bell pepper, diced provides sweetness and vibrant hue

– 2 cups shredded cheddar cheese melts for gooey richness

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Instructions

1-First Step: Mise en Place Preheat your oven to 350°F (175°C) and grease a 9 x 13-inch baking pan. Chop 4 green onions, dice 1/2 green bell pepper and 1/2 red bell pepper. This takes about 5 minutes and sets you up for smooth assembly. For dietary needs, use plant-based sausage for vegan versions.

2-Second Step: Prepare Sausage Brown 2 pounds sausage in a skillet over medium heat, breaking it into small pieces. Drain excess grease. This step builds the savory base for your sausage and cheese breakfast casserole. Turkey sausage works for lower fat.

3-Third Step: Make the Custard Mixture In a large bowl, whisk together 12 eggs, 1 cup sour cream, 1/4 cup milk, 2 cups shredded cheddar cheese, 1 teaspoon salt, and 1/2 teaspoon ground black pepper until smooth. This creates the binding custard. For lighter options, use egg whites or reduced-fat dairy.

4-Fourth Step: Add Sausage and Veggies Stir the browned sausage into the egg mixture. Saute the diced bell peppers and chopped green onions in the same skillet for 2 to 3 minutes, then fold them in. Mix well for even distribution in this easy make ahead Christmas breakfast casserole with eggs sausage and cheese.

5-Fifth Step: Bake Pour the mixture into the prepared pan. Bake at 350°F for 35 to 50 minutes, until edges set and center is slightly jiggly. Total time runs about 1 hour 5 minutes including 10 minutes prep. For convection ovens, check at 30 minutes. Vegan versions may need extra time for firmness.

6-Sixth Step: Rest and Serve Let cool slightly before slicing into 12 servings. Garnish with extra green onions if desired. Pair with fruit for balance. Reheat leftovers safely as noted later.

Last Step:

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Notes

🌙 Prepare through step 5 the night before, cover, and refrigerate; bake in the morning
🧊 For longer storage, freeze the casserole before baking (wrap tightly in plastic wrap and foil), thaw overnight in the fridge before baking
🍽️ Swap cheddar for pepper jack or Swiss, or add vegetables like spinach or zucchini for variety

Author: Brandi Oshea
Prep Time: 10 minutes
Cooling time: 5 minutes
Cook Time: 50 minutes
Category: Breakfast
Method: Baking
Cuisine: American
Diet: None

Nutrition

Serving Size: 1 serving
Calories: 385
Sugar: 1
Sodium: 669
Fat: 30
Saturated Fat: 12
Unsaturated Fat: 18
Trans Fat: 0
Carbohydrates: 2
Fiber: 0
Protein: 23
Cholesterol: 239