Croque Monsieur Casserole (Printable Version)

A comforting twist on the classic French bistro sandwich, layering buttery bread, ham, Gruyère, and béchamel for a decadent meal.

# What You'll Need:

→ Bread & Dairy

01 - 12 slices white sandwich bread, crusts removed
02 - 2 tablespoons unsalted butter, softened (plus extra for greasing)
03 - 1 1/2 cups Gruyère cheese, grated (or Swiss cheese)
04 - 1 cup whole milk
05 - 1/2 cup heavy cream
06 - 3 large eggs

→ Meats

07 - 8 slices cooked ham (about 7 ounces)

→ Béchamel Sauce

08 - 2 tablespoons unsalted butter
09 - 2 tablespoons all-purpose flour
10 - 1 1/4 cups whole milk
11 - 1/4 teaspoon ground nutmeg
12 - Salt and black pepper, to taste

# Directions:

01 - Preheat oven to 375°F. Lightly butter a 9x13-inch baking dish.
02 - Melt 2 tablespoons butter in a medium saucepan over medium heat. Whisk in flour and cook for 1 minute. Gradually whisk in 1 1/4 cups milk, stirring constantly, until thickened and smooth (about 3-4 minutes). Season with nutmeg, salt, and pepper. Remove from heat.
03 - Butter one side of each bread slice. Arrange half the bread, buttered side down, in the prepared dish. Top with half the ham slices and half the Gruyère. Repeat layers with remaining bread (buttered side down), ham, and cheese.
04 - Whisk together eggs, 1 cup milk, cream, and a pinch of salt in a bowl. Pour evenly over the casserole, pressing gently to soak the bread.
05 - Pour the béchamel sauce over the top and spread evenly. Bake uncovered for 35-40 minutes, or until puffed, golden, and bubbling. Let rest 10 minutes before serving.

# Expert Suggestions:

01 -
  • It transforms an already perfect sandwich into something even more comforting and shareable
  • The overnight prep means you can wake up and slide it into the oven for company
  • That béchamel soaking into the bread creates pockets of creamy decadence in every single bite
02 -
  • The bread needs to absorb the custard for at least 15 minutes before baking, so don't rush this step
  • Letting it rest for 10 minutes after baking is crucial—it will deflate slightly and set up for cleaner serving
03 -
  • Grate your own cheese instead of buying pre-grated—it melts so much better into the sauce
  • If the top is browning too quickly, tent loosely with foil for the last 10 minutes
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