# Easy Sausage and Egg Breakfast Casserole

This breakfast casserole layers sausage, vegetables, cheese and bread in a savory egg custard. It bakes into a golden, puffed bake that feeds a crowd.

You can assemble it the night before, so on the morning you only have to slide it into the oven.

- Total time: 1 h 5 min (prep 15 min, cook 50 min)
- Serves: 8
- Per serving (estimated): 380 kcal, 22 g protein
- Cuisine: American. Category: Breakfast.

## Ingredients

- 450 g breakfast sausage
- 1/2 onion, diced
- 1 red bell pepper, diced
- 6 cups (about 300 g) day-old bread, cubed
- 200 g cheddar cheese, shredded
- 8 eggs
- 2 cups milk
- 1 tsp mustard powder or Dijon
- 1/2 tsp salt
- 1/2 tsp black pepper
- 1 tbsp butter, for the dish

## Method

1. Butter a 9 by 13 inch (23 by 33 cm) baking dish.
2. Brown the sausage in a large skillet over medium-high heat for 6 to 8 minutes, breaking it up, until no pink remains. Spoon out the sausage and leave 1 tbsp fat in the pan.
3. Cook the onion and pepper in that fat over medium heat for 4 minutes, until soft.
4. Spread half the bread cubes in the dish, then half the sausage, vegetables and cheese. Repeat with a second layer.
5. Whisk the eggs, milk, mustard, salt and pepper until smooth. Pour evenly over the dish.
6. Press the bread down so it soaks, cover and chill for at least 30 minutes, or overnight.
7. Heat the oven to 350°F (175°C). Uncover the dish and bake 45 to 50 minutes, until the top is golden and the center springs back, reaching 160°F (71°C) on a thermometer.
8. Rest 10 minutes before cutting into squares.

## Why it works

- Browning the sausage first adds deep, savory flavor and keeps the casserole from turning greasy.
- Day-old bread is dry, so it soaks up the egg mix without falling apart.
- A rest in the fridge lets the bread fully absorb the custard for an even, tender texture.
- Baking at a moderate 350°F sets the eggs gently so they stay soft instead of rubbery.
- Resting before cutting lets the custard finish setting so the squares hold together.

## The science

- **Egg custard sets gently.** The egg proteins in a custard start to thicken around 150°F (65°C) and tighten as they climb. Baking at a moderate temperature sets them slowly so they stay tender. Very high heat squeezes out water and makes the casserole watery.
- **Why stale bread works best.** Dry bread has less moisture in its crumb, so it acts like a sponge and takes in far more of the egg mix. Fresh, soft bread is already full of water and turns into paste. Toast fresh bread cubes briefly to fix that.

## Tips

- Cube bread to about 1 inch so the pieces absorb evenly.
- Place the dish on a baking sheet in case any custard bubbles over.
- Check the center with a thermometer; 160°F (71°C) means it is set and safe.

## Mistakes to avoid

- Skipping the rest leaves dry bread on top and a pool of egg at the bottom, so let it soak first.
- Using fresh soft bread makes the bake mushy, so dry the cubes in the oven first.
- Cutting right out of the oven makes it fall apart, so rest it for 10 minutes.

## Variations and swaps

- Swap the sausage for diced ham and add spinach.
- Make it vegetarian with mushrooms, spinach and extra cheese.
- Add a spoon of salsa over the top before baking for a Tex-Mex version.
- Swap breakfast sausage for crumbled bacon; it adds a smokier flavor.
- Swap cheddar for Gruyere or Monterey Jack for a milder, meltier cheese.
- Swap bread for frozen hash brown potatoes; the dish becomes gluten-free.

## Storage

Refrigerate covered for up to 4 days or freeze portions for 2 months. Reheat slices in the microwave or a 350°F (175°C) oven until they reach 165°F (74°C).

## FAQ

**Can I make breakfast casserole the night before?**

Yes. Assemble the dish, cover it and refrigerate for up to 24 hours. Bake it straight from the fridge and add 5 to 10 minutes to the time.

**How do I know breakfast casserole is done?**

It is done when the top is golden, the center no longer jiggles and a thermometer in the middle reads 160°F (71°C). A knife in the center should come out clean.

**Can I freeze breakfast casserole?**

Yes, bake it, cool it fully, then freeze portions for up to 2 months. Thaw overnight in the fridge and reheat until steaming hot.

**Why is my breakfast casserole watery?**

Watery casserole comes from too many wet vegetables, too little bread, or an oven that is too hot. Cook vegetables first and use dry bread.

**What bread is best for breakfast casserole?**

Use sturdy day-old bread such as French bread, sourdough or plain white sandwich bread. Avoid very soft or very sweet loaves.

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Source: https://cookingscientist.com/recipes/breakfast-casserole (Cooking Scientist). Learn the science of cooking in the Cooking Scientist app for iPhone and iPad: https://apps.apple.com/app/id6830326846