Croque Monsieur Casserole

Today we are talking about the Croque Monsieur. If you have never had one, it is a french sandwich with ham, Gruyere cheese, mustard, and it’s topped with Béchamel sauce and is then broiled in the oven until perfectly bubbly and gooey. So in other words, it’s basically heaven!

Croque Monsieur Casserole

Today I’m sharing this fun breakfast or brunch twist on the french classic – Croque Monsieur Casserole! This casserole is simple, but seems seriously impressive. And best of all, you can prep it the night before which means it’s perfect for Christmas morning!

To make it, you just need a day old baguette of french bread. Slice it up, spread a bit of butter on each slice, stick some ham in between each slice of the bread in a baking dish. Then I mix up the custard base with eggs, some half and half, a bit of dijon mustard, shredded gruyere and a bit of Parmesan cheese, some herbs like thyme. Pour that over the bread, cover and chill overnight! In the morning, it just needs to bake for about 50-60 minutes.

One thing to note is the baking dish size in the recipe, I find a typical 9×13 baking dish to be a bit too large for the standard size french baguette which is about 26 inches long. I had a smaller baking dish that is 7×11 and the bread fit perfectly in that size baking dish. I realize that’s kind of an odd size that many may not have. You can still make it in a 9×13, but the bread will be more spread out. You can also try an 8×8, but may need to leave some of the bread out.

You don’t have to prep this the night before, but I do recommend letting the egg mixture sit with the bread for at least an hour before baking so it soaks all that goodness up in the custard. If you don’t need it first thing in the morning (like if you plan to serve it for brunch), then you can prep it the morning of. If you do chill it over night, I also recommend letting it come to room temperature before baking.

Croque Monsieur Casserole

Croque Monsieur Casserole
Yield: 6 servings

Croque Monsieur Casserole

Prep Time 20 minutes
Cook Time 1 hour
Total Time 1 hour 20 minutes

Croque Monsieur Casserole - a twist on the classic French sandwich! This prep-ahead casserole is perfect for holiday breakfasts or brunch!


  • 1 day old french baguette (approx. 26 inches)
  • 3 tablespoons salted butter
  • 6 ounces thinly sliced ham
  • 6 large eggs
  • 1 cup half and half
  • 1 cup whole milk
  • 1 teaspoon dried thyme
  • 2 tablespoons dijon mustard (optional)
  • 1/4 cup grated Parmesan cheese
  • 1 1/2 cups grated Gruyere cheese
  • 1/2 teaspoon kosher salt (or to taste)


  1. Spray a baking dish approximate 7x11or 8x11 with cooking spray. Slice the baguette into slices about 1/2-inch thick. Spread a little bit of butter on one side of each bread. Arrange the slices in the baking dish sitting upwards (see photos).
  2. Cut the ham into smaller slices and stick a piece in between each slice of the bread. Set aside.
  3. In a mixing bowl, whisk together the eggs, half and half, milk, mustard, salt, thyme, the gruyere and Parmesan cheese until the eggs are completely broken up and well-mixed. Pour the mixture evenly over the bread. Cover with foil and refrigerate for at least one hour or overnight.
  4. Preheat oven to 350 degrees F. If chilled overnight, let casserole sit out for about 30 minutes before baking. Bake the casserole for 50-60 minutes or until the custard has set.


Recipe adapted from New York Times

Nutrition Information:



Serving Size:


Amount Per Serving: Calories: 540Total Fat: 31gSaturated Fat: 16gTrans Fat: 1gUnsaturated Fat: 12gCholesterol: 277mgSodium: 1380mgCarbohydrates: 34gFiber: 1gSugar: 7gProtein: 32g

Croque Monsieur Casserole