This French onion breakfast casserole with croissants is as easy as it is delicious. It’s the perfect holiday breakfast you can make ahead, and it will have your guests coming back for seconds, maybe even thirds. It’s that good! The only part that takes some time is the caramelized onions. Other than that, it comes together pretty quickly.
A few croissants, eggs, some bacon, onions, gruyere cheese, a little milk, and you’re on your way to a savory breakfast treat.
This casserole was inspired by our last trip to France. Even though it was raining and cold on our last night in Paris, we headed out anyway to enjoy one last evening of fun. After wandering the back streets of Saint Germain we ended up in front of Cafe de Flore. As luck would have it, we were hungry after all the walking and we decided to sit outside and enjoy one last bistro meal – at least for this trip.
After a few minutes of looking over the menu and debating the pros and cons of each item listed, we both landed on French onion soup. The soup was the perfect choice to eat outside, under the awning of course, on a cold and rainy Paris night. And since then, I’ve continued to obsess about a good French onion soup.
Having French onions on my mind and deciding what I wanted to serve on Christmas morning, I decided to try making a French onion breakfast casserole inspired by Cafe du Flore’s French onion soup. It turned out great and you can serve it for breakfast but it’s also perfect for brunch. We think you’ll like it too.
The best thing about this recipe, it’s just as good as leftovers. Just place them in the oven and cover them loosely with aluminum foil until warm.
The equipment you’ll need for making French onion breakfast casserole with croissants
- Large skillet
- Baking dish
- Large bowl
- Sharp knife
- Box cheese grater
- Whisk
- Liquid measuring cup
The ingredients
- Kosher salt
- Black pepper
- Eggs
- Gruyere cheese
- Milk
- Bacon
- Onions
- Croissants (day-old or frozen works just fine)
- Butter
Instructions for making French onion breakfast casserole with croissants
French Onion Breakfast Casserole With Croissants
This French onion breakfast casserole with croissants is as easy as it is delicious. It’s the perfect holiday breakfast you can make ahead, and it will have your guests coming back for seconds, maybe even thirds. It’s that good!
- Prep Time: 20 minutes
- Cook Time: 60 minutes
- Total Time: 1 hour 20 minutes
- Yield: 12 servings 1x
- Category: Breakfast
- Method: Baking
- Cuisine: French
Ingredients
- 1/2 teaspoon kosher salt
- 1/4 teaspoon black pepper
- 12 eggs
- 1 cup shredded gruyere cheese
- 1/2 cup milk
- 8 oz. Bacon
- 4 onions
- 6 large croissants (day-old or frozen works just fine)
- 4 tablespoons butter
Instructions
- Preheat over to 350 degrees.
- Using a sharp knife or mandolin, slice the onions very thinly.
- Grate the cheese.
- Slice the croissants into bite-sized pieces.
- Cook the bacon until crispy, drain, and set aside.
- Add the butter to the skillet, melt, and add the onion. Then, add the eight tablespoons of water and cook. Once the butter has been absorbed and the water has evaporated, drizzle some olive oil over the onions and stir. Stir the onions regularly until they are caramelized and golden brown.
- Drain most of the bacon grease from the skillet and add the onions to take on the bacon flavor.
- In a large bowl, add the eggs, milk, salt, and pepper and whisk vigorously until the egg mixture is completely combined.
- Grease a 9″ X 13″ baking dish with butter.
- Spread the croissant pieces evenly over the bottom of the pan.
- Spread the caramelized onions over the croissant pieces.
- Chop the bacon into bite-sized pieces and spread on top of the onions.
- Carefully pour the egg mixture over the top of the croissants, onions, and bacon.
- Sprinkle the grated cheese evenly over the top.
- Bake for 25 to 30 minutes, remove from oven, and let cool slightly before serving.
Can I substitute any ingredients?
You could use sausage instead of bacon. However, adding the onions to the pan you cooked the bacon in adds such a great intense flavor. I don’t think you’d get the same result with sausage.
You could also use heavy cream instead of milk. But the croissants are rich enough which is why I think milk is a better choice.
I considered adding herbs de Provence to the onions. But I wanted this to have the same flavors as French onion soup so I decided to let the caramelized onions and bacon add all the flavoring.
What can I serve French onion breakfast casserole with?
If you’re serving it for breakfast, you don’t really need anything else. However, you could serve homemade hash browns with it. They would be delicious.
If you’re serving this for brunch, I think a nice green salad with a simple light dressing would work perfectly.
sounds delicious, can you clarify that you use the same skillet for cooking the bacon and the onions or are there two skillets? do you add the onions to a separate skillet that has a little bacon grease left in? thank you!
Sorry I didn’t make that more clear. I use two different pans. I cook the bacon in a cast iron skillet, remove the bacon when done and discard most of the oil. I cook the onions in a different pan and when they are caramelized I add them to the skillet the bacon was in. I hope that answers your question.
thanks, I thought that’s the way you did it. I plan to try halving the recipe since I’m the only one who really loves onions. Happy Christmas!
I was struggling to decide on an additional dish for Christmas brunch and this fits the bill perfectly!! Thank you!
It’s so good! Perfect for the holidays!
Wanted to let you know that the casserole was an enormous hit! Everyone loved how delicous and different it was. I had a small chunk of leftover brie and added that to the mix as well, because “more French cheese, why not?”. This one is definitely a keeper!