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Savory Croissant Breakfast Casserole Recipe by Mr. Make It Happen
Why You’ll Love This Croissant Breakfast Casserole
This recipe is a beautiful marriage of buttery croissants, creamy custard, crispy bacon, and savory sausage, all held together with gooey cheese. The Dijon mustard adds a hint of tang, while the sage and red pepper flakes give it a cozy, herby kick.
It’s an all-in-one dish that requires minimal prep but offers maximum flavor. Plus, it can be made ahead, so you can just pop it in the oven on the morning of your event and focus on enjoying your company.
Whether you’re serving it at a holiday brunch, a family breakfast, or a weekend gathering with friends, this croissant breakfast casserole will become a favorite that everyone will ask for again and again.
Enjoy!
Are you craving a breakfast that feels indulgent but is still easy to prepare? Look no further than this Savory Croissant Breakfast Casserole—a perfect dish for a leisurely weekend brunch, a holiday breakfast, or even meal prep for the week ahead.
With flaky croissants, creamy eggs, savory bacon and sausage, and a melty cheese blend, this casserole is a total crowd-pleaser. It combines all the best elements of a comforting breakfast in one delicious, fuss-free dish.
Prepare the Croissants:
Start by cutting your croissants into large chunks (about 1-2 inch pieces). If your croissants are fresh, it’s helpful to let them sit out for a little while so they dry out slightly. Stale or day-old croissants will absorb the custard mixture better, but fresh will still work beautifully.
Dice your onion and roughly chop the spinach. Next, grate your cheese and set aside until we need it.
Mr. Make It Happen
Japanese Steel Chef Knife
Cook the Meat:
In a large skillet, cook the bacon until crispy, then transfer it to a paper towel-lined plate to drain. In the same skillet, cook the breakfast sausage over medium heat until browned and fully cooked. Once both meats are ready, crumble the bacon and sausage into bite-sized pieces and set aside.
Sauté the Vegetables:
In the same skillet, add a little bit of bacon grease or olive oil and sauté the diced onion until soft and translucent, about 5 minutes. Add the spinach and cook for an additional 1-2 minutes, until wilted. Remove from heat and set aside.
Prepare the Custard Mixture:
In a large mixing bowl, whisk together the eggs, heavy cream, Dijon mustard, dry sage, all-purpose seasoning, and red pepper flakes. Whisk until well combined and smooth.
Assemble the Casserole:
Grease a 9×13-inch baking dish and then layer the croissant pieces evenly on the bottom. Spread the sautéed onions and spinach over the croissants, followed by the cooked bacon and sausage. Sprinkle half of the shredded Gruyère and cheddar cheeses over the top.
Now, pour the egg mixture evenly over the casserole, making sure the croissants are well-coated. Gently press the croissants down into the custard with a spoon to ensure everything soaks in. Top with the remaining cheese.
Let It Soak:
Cover the casserole with aluminum foil and refrigerate it for at least 30 minutes to allow the croissants to absorb the egg mixture. If you have time, you can refrigerate it overnight, which will make the casserole even more flavorful.
Bake:
Preheat your oven to 350°F (175°C). Once ready, bake the casserole (covered with foil) for 30 minutes. After 30 minutes, remove the foil and bake for an additional 15-20 minutes, or until the casserole is golden brown on top and the eggs are set. You can check for doneness by inserting a knife into the center—if it comes out clean, it’s ready.
Garnish and Serve:
Once baked, sprinkle freshly grated Parmesan over the top and garnish with chopped chives for a pop of color and flavor. Let the casserole rest for a few minutes before serving.
Tips and Variations:
- Vegetarian Version: Skip the bacon and sausage, and add extra veggies like mushrooms, bell peppers, or zucchini for a hearty vegetarian option.
- Cheese Choices: Swap out Gruyère and cheddar for any cheese you prefer—fontina, mozzarella, or even a sharp blue cheese can add a fun twist.
- Make It Ahead: This casserole can be made up to a day ahead. Just cover it tightly and refrigerate overnight. It’s perfect for a hassle-free brunch.
- Add More Heat: If you like it spicy, consider adding a little more red pepper flakes or even a drizzle of hot sauce on top before baking.
Croissant Breakfast Casserole: Print & Download Recipe
Croissant Breakfast Casserole
Ingredients
- 8 large croissants, day-old works best, but fresh is fine too
- 8 large eggs
- 3 cups heavy cream
- 2 tsps dry sage
- 1 tsp all-purpose seasoning, like garlic powder, onion powder, salt, and pepper mix
- ½ tsp red pepper flakes, optional for a little heat
- 1 cup fresh spinach, chopped
- 1 medium onion, diced
- 1 cup Gruyère cheese, shredded
- 1 cup white cheddar cheese, shredded
- 1 tbsp Dijon mustard
- ½ lb bacon, cooked and crumbled
- 1 lb breakfast sausage, cooked and crumbled
- Freshly grated Parmesan, for topping
- Chopped chives, for garnish
Instructions
Prepare the Croissants:
- Start by cutting your croissants into large chunks (about 1-2 inch pieces).
- If your croissants are fresh, it’s helpful to let them sit out for a little while so they dry out slightly.
- Stale or day-old croissants will absorb the custard mixture better, but fresh will still work beautifully.
- Dice your onion and roughly chop the spinach. Next, grate your cheese and set aside until we need it.
Cook the Meat:
- In a large skillet, cook the bacon until crispy, then transfer it to a paper towel-lined plate to drain.
- In the same skillet, cook the breakfast sausage over medium heat until browned and fully cooked.
- Once both meats are ready, crumble the bacon and sausage into bite-sized pieces and set aside.
Sauté the Vegetables:
- In the same skillet, add a little bit of bacon grease or olive oil and sauté the diced onion until soft and translucent, about 5 minutes.
- Add the spinach and cook for an additional 1-2 minutes, until wilted.
- Remove from heat and set aside.
Prepare the Custard Mixture:
- In a large mixing bowl, whisk together the eggs, heavy cream, Dijon mustard, dry sage, all-purpose seasoning, and red pepper flakes.
- Whisk until well combined and smooth.
Assemble the Casserole:
- Grease a 9×13-inch baking dish and then layer the croissant pieces evenly on the bottom.
- Spread the sautéed onions and spinach over the croissants, followed by the cooked bacon and sausage.
- Sprinkle half of the shredded Gruyère and cheddar cheeses over the top.
- Now, pour the egg mixture evenly over the casserole, making sure the croissants are well-coated.
- Gently press the croissants down into the custard with a spoon to ensure everything soaks in.
- Top with the remaining cheese.
Let It Soak:
- Cover the casserole with aluminum foil and refrigerate it for at least 30 minutes to allow the croissants to absorb the egg mixture.
- If you have time, you can refrigerate it overnight, which will make the casserole even more flavorful.
Bake:
- Preheat your oven to 350°F (175°C).
- Once ready, bake the casserole (covered with foil) for 30 minutes.
- After 30 minutes, remove the foil and bake for an additional 15-20 minutes, or until the casserole is golden brown on top and the eggs are set.
- You can check for doneness by inserting a knife into the center—if it comes out clean, it’s ready.
Garnish and Serve:
- Once baked, sprinkle freshly grated Parmesan over the top and garnish with chopped chives for a pop of color and flavor.
- Let the casserole rest for a few minutes before serving.
Notes
- Vegetarian Version: Skip the bacon and sausage, and add extra veggies like mushrooms, bell peppers, or zucchini for a hearty vegetarian option.
- Cheese Choices: Swap out Gruyère and cheddar for any cheese you prefer—fontina, mozzarella, or even a sharp blue cheese can add a fun twist.
- Make It Ahead: This casserole can be made up to a day ahead. Just cover it tightly and refrigerate overnight. It’s perfect for a hassle-free brunch.
- Add More Heat: If you like it spicy, consider adding a little more red pepper flakes or even a drizzle of hot sauce on top before baking.
