Croque Monsieur Breakfast Casserole
There’s so much to love about this Croque Monsieur Breakfast Casserole. It’s easy to make, and it’s cheesy and loaded with flavor from prosciutto and gruyere. Everyone loves this easy casserole recipe which is perfect for lazy weekend brunches or even weeknight dinner!
We learned how to make this delicious Croque Monsieur Breakfast Casseroles on one of our travels through France. We stayed at the Chateau de ValCreuse in La Roche Posay and made this delicious dish for breakfast.
Croque Monsieur Breakfast Casserole
Loaded with flavor from Dijon mustard, gruyere cheese, and prosciutto, it’s a tasty twist on an American classic. You can easily double the recipe, and unlike many breakfast casseroles, this one doesn’t need to set up overnight. But, it works beautifully to let it sit overnight, if you are planning ahead for breakfast the next morning.
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Grab your croissants and prosciutto and make something amazing for brunch this weekend! Try it at home–you don’t need to be in France for this recipe :)
I love gathering around the table with friends and family for brunch, and this amazing Croque Monsieur Breakfast Casserole is the perfect meal to share. It makes enough to serve about 8, but you can easily double it. It’s a straightforward recipe with easy-to-find ingredients. You’ll need croissants for this dish, and they’re best if they’re a day old. I buy them and leave them on the counter overnight. If they’re a bit stale, they soak up more of the eggy and cheesy custard.
Why I love this recipe
- It’s pretty easy to make, and you can prep it ahead of time, even the night before, and keep it in the fridge until you’re ready to bake it.
- You can make some easy ingredient swaps to customize it – see my suggestions below.
- You can easily double it to feed a crowd.
Gather these ingredients
- Croissants – You’ll need 7 large day-old croissants.
- Prosciutto – About 6 ounces, torn into pieces.
- Gruyere cheese – Shredded.
- Eggs
- Milk
- White wine
- Dijon mustard
- Flour – All purpose flour.
- Butter
- Salt and cracked black pepper
- Basil – Optional garnish.
- Heirloom tomatoes – Optional garnish.
How to make Croque Monsieur Breakfast Casserole
- Make the bechamel sauce by melting 2 tablespoons of the butter in a small saucepan over medium-low heat. Add the flour and whisk while cooking until the butter and flour are well mixed and foaming. About 2 minutes.
- Slowly stream in the milk, whisking as you pour until it is smooth and is starting to thicken.
- Turn off the heat and whisk in the mustard, salt, and pepper. Set aside.
- Preheat your oven to 350-F and grease a 9×13-inch baking dish with the remaining tablespoon of butter.
- Slice the croissants in half lengthwise and lay the bottom halves in the pan, squishing them together gently so they fit.
- Brush each half with a generous layer of bechamel sauce.
- Layer the torn pieces of prosciutto and all but ¼ cup of the shredded cheese over the croissants.
- Add the croissant tops to the bottoms in the baking dish and squish them a bit to fit.
- Whisk together the eggs, milk, white wine, mustard, and a pinch of salt and pepper, then pour this mixture over the croissants. Press down gently with your hands to help the croissants absorb the mixture.
- Top with the remaining cheese and let sit for about 30 minutes before baking at 350-F uncovered, for about 35-40 minutes.
- Cut into squares and garnish with chopped tomato and basil and serve. Enjoy!
Tips & substitutions
- Slightly stale croissants are perfect for this dish because they’ll soak up more of the egg custard.
- You can use swiss cheese instead of gruyere or use your favorite sharp cheddar.
- You can use ham instead of prosciutto for a slightly different flavor.
- This casserole can be made up to 12 hours in advance. Cover it and keep it in the fridge until you’re ready to bake. You may need to add some extra baking time if it is super cold.
Serving suggestions for Croque Monsieur Breakfast Casserole
This Croque Monsieur Breakfast Casserole is perfect all on its own, but I love serving it with other brunch favorites like fruit salad, muffins, and my favorite Honey-Pepper Bacon.
It’s perfect on its own with a glass of sangria or a hot coffee, or you can make it a part of an elaborate brunch spread. It’s wonderful for Christmas brunch, but it really is great any time of the year.
Storage
Store any leftovers in an airtight container in the fridge for 3-4 days. You can reheat leftovers in the microwave or covered in the oven at low heat.
Check out these awesome breakfast casserole recipes while you’re here
- Pear-Croissant Breakfast Casserole
- Green Chili Casserole
- Amish Breakfast Casserole
- French Onion Croissant Bake
Get the Recipe:
Croque Monsieur Breakfast Casserole
Ingredients
- 7 large day old croissants
- 6 oz prosciutto, torn into pieces
- 1 cup 8 oz shredded Gruyère or Swiss cheese
- 6 large eggs
- 1 c milk
- ¼ c white wine
- 1 tsp Dijon mustard
- 1 tsp kosher salt
- Black cracked pepper
Béchamel Sauce
- 2 tbsp flour
- 3 tbsp butter
- 1 ½ c milk
- 2 tbsp mustard dijon
- 1 tsp kosher salt
- Black cracked pepper
- Fresh garden tomatoes, chopped for garnish
- Fresh chopped basil, garnish
Instructions
Make the Béchamel sauce:
- In a small saucepan, melt 2 Tbsp of butter over medium-low heat. Add the flour and whisk while cooking, until the butter and flour are well combined and foaming, about 2 minutes. Slowly add the milk, continuing to whisk until the mixture is light in color and smooth and starting to thicken up. Turn off the heat, whisk in the mustard, salt, and freshly cracked pepper. Set aside.
Prepare the casserole:
- Preheat your oven to 350 F. Grease a 9×13 inch baking dish with the remaining 1 Tbsp of butter.
- Slice the croissants in half through the middle (lengthwise) so you have a top and bottom. Lay the bottoms into the pan, squishing them together. Brush each half with a generous layer of béchamel sauce. Any extra, put on the bottom layer.
- Next, layer the torn pieces of prosciutto and then the shredded cheese, reserving about 1/4 cup of cheese to add at the end.
- Place the tops back onto the bottoms in the baking dish. If they don’t fit perfectly, you can rearrange them. They will be squished together.
- Whisk together the eggs, milk, white wine, mustard, and a pinch of salt and pepper. Pour the mixture over the croissants. With your hands, press down on the croissants to help them absorb the egg mixture. Top with the remaining cheese. Let sit for 30 minutes (or up to 12 hrs) before baking.
- Bake uncovered for 35-40 minutes until golden brown. Serve right away while hot!
- Serve an individual serving with a spoonful of fresh heirloom chopped tomatoes and fresh basil.
Hello and welcome to my home and table!
I’m Sandy—lover of food, family, cooking, THE BIG BOARD, travel, and bringing people together. Through great recipes and connection around the table, we become better, stronger, and more courageous people. Feasting on Life is real, and every time we do it, we grow a little more. Read more...
Can this be frozen?
I have not tried freezing this BF casserole. I’m not sure how it would freeze with the eggs, so I probably wouldn’t do it.