BREAKFAST CASSEROLE
Having a go-to breakfast casserole recipe can be a lifesaver for brunch parties or when hosting overnight guests. It takes a little planning, but you can do the majority of the work ahead of time and just cook it in the morning. I love the thought of sneaking down to the kitchen while everyone is still asleep and popping a big baking dish of hearty goodness into the oven so guests wake up to the smell of breakfast waiting for them. SERVES 8 TO 10
PREP TIME: 10 minutes
COOK TIME: 1 hour, 40 minutes
3 tablespoons (45 ml) extra-virgin olive oil, divided
¼ onion, chopped (2 to 3 tablespoons (45 ml))
1 garlic clove, minced
1 large sweet potato, diced
8 ounces mushrooms, sliced
Salt
Freshly ground black pepper
10 ounces breakfast sausage
10 eggs
2 tablespoons (30 ml) sliced scallion, for garnish
- Preheat the oven to 350°F (180°C).
- In a large skillet over medium heat, heat 1½ tablespoons of olive oil. Sauté the onion and garlic until the onion is slightly translucent, about 5 minutes. Add the sweet potato, and cook until fork-tender, about another 15 minutes. Spoon the mixture into an 8-by-12-inch baking dish.
- Add the remaining 1½ tablespoons of olive oil to the skillet, and sauté the mushrooms until browned, 5 to 7 minutes. Season with salt and pepper, and add them to the baking dish as a second layer.
- Add the sausage to the skillet, and cook until no more pink remains, 7 to 10 minutes. Season with salt and pepper, and add to the baking dish as a third layer.
- In a large bowl, whisk the eggs well, season with salt and pepper, and pour over the casserole mixture in the baking dish. Bake for about 1 hour, or until the eggs are no longer runny.
- Serve hot, garnished with a sprinkle of sliced scallion.
VARIATION 1 BLT CASSEROLE: Replace the sausage with bacon, and serve the casserole topped with ½ cup chopped lettuce and a side of Ranch Dressing (here).
VARIATION 2 PIZZA CASSEROLE: For meat lovers, skip the sweet potato and add 6 ounces sliced pepperoni to the casserole dish. Serve with a side of warm (sugar-free) pizza sauce.
PREP TIP: Assemble the casserole up to the end of step 4 ahead of time, and refrigerate until ready to bake. Add the eggs and bake the morning you plan to serve the casserole.
More Recipes You'll Love
- Fiery Frittata
- Scrambled Eggs with Spring Onions, Mushroom and Tomato Breakfast
- Cheesy Tomato Frittata
This breakfast casserole layers fork-tender sweet potato, browned mushrooms, and savory breakfast sausage in a baking dish, then pours ten whisked eggs over the top and bakes for an hour. It is the brunch dish that feeds a crowd while you sleep in. Scallions on top keep every bite fresh.
Pro Tips
- Build the casserole in layers - sweet potato first, then mushrooms, then sausage - seasoning each layer as it goes into the dish.
- Cook the sweet potato until truly fork-tender, about 15 minutes, before it goes into the baking dish. It keeps cooking in the oven.
- Do most of the work ahead: assemble through the sausage layer and refrigerate, then whisk the eggs and bake the morning you serve it.
- Bake until the eggs are no longer runny - roughly an hour at 350°F.
- Easy variations: swap the sausage for bacon and top with chopped lettuce BLT-style, or skip the sweet potato and add sliced pepperoni for a pizza casserole.
Frequently Asked Questions
Is breakfast casserole paleo?
It is, with a compliant breakfast sausage - eggs, sweet potato, mushrooms, onion, and sausage. Check the sausage label for fillers.
Can I make this casserole ahead of time?
Yes. Assemble it through the sausage layer and refrigerate overnight, then pour the whisked eggs over before baking in the morning.
How many people does it serve?
Eight to ten. It is designed for brunch parties and overnight guests.
How long do leftovers keep?
Leftovers refrigerate well for up to 4 days and rewarm in the oven or microwave.
Recipe Card

Ingredients
Method
- Preheat the oven to 350°F.
- In a large skillet over medium heat, heat 1½ tablespoons of olive oil.
- Sauté the onion and garlic until the onion is slightly translucent, about 5 minutes.
- Add the sweet potato, and cook until fork-tender, about another 15 minutes. Spoon the mixture into an 8-by-12-inch baking dish.
- Add the remaining 1½ tablespoons of olive oil to the skillet, and sauté the mushrooms until browned, 5 to 7 minutes.
- Season with salt and pepper, and add them to the baking dish as a second layer.
- Add the sausage to the skillet, and cook until no more pink remains, 7 to 10 minutes.
- Season with salt and pepper, and add to the baking dish as a third layer.
- In a large bowl, whisk the eggs well, season with salt and pepper, and pour over the casserole mixture in the baking dish.
- Bake for about 1 hour, or until the eggs are no longer runny.
- Serve hot, garnished with a sprinkle of sliced scallion.




