Croque Monsieur Casserole (Printable)

Layers of buttery bread, ham, Gruyère, and béchamel baked to golden perfection for ultimate comfort.

# Ingredient List:

→ Bread & Dairy

01 - 12 slices white sandwich bread, crusts removed
02 - 4 tablespoons unsalted butter, softened (plus extra for greasing)
03 - 1.5 cups Gruyère cheese, grated
04 - 1 cup whole milk
05 - 0.5 cup heavy cream
06 - 3 large eggs

→ Meats

07 - 8 slices cooked ham, approximately 7 ounces

→ Béchamel Sauce

08 - 2 tablespoons unsalted butter
09 - 2 tablespoons all-purpose flour
10 - 1.25 cups whole milk
11 - 0.25 teaspoon ground nutmeg
12 - Salt and black pepper to taste

# How-To Steps:

01 - Preheat oven to 375°F. Lightly butter a 9x13-inch baking dish and set aside.
02 - Melt 2 tablespoons butter in a medium saucepan over medium heat. Whisk in flour and cook for 1 minute. Gradually whisk in 1.25 cups milk, stirring constantly, until thickened and smooth, approximately 3 to 4 minutes. Season with nutmeg, salt, and pepper. Remove from heat.
03 - Butter one side of each bread slice. Arrange half the bread slices with buttered side down in the prepared baking dish.
04 - Top bread with half the ham slices and half the Gruyère cheese. Repeat layers with remaining bread (buttered side down), ham, and cheese.
05 - Whisk together eggs, 1 cup milk, heavy cream, and salt in a bowl. Pour evenly over the casserole, pressing gently to allow bread to absorb liquid.
06 - Pour prepared béchamel sauce over the casserole and spread evenly across the surface.
07 - Bake uncovered for 35 to 40 minutes until puffed, golden brown, and bubbling at the edges. Allow to rest 10 minutes before serving.

# Expert Hints:

01 -
  • All the buttery, cheesy joy of a croque monsieur without standing over a skillet flipping sandwiches.
  • The béchamel soaks into the bread and creates this custardy, golden top layer that tastes like pure comfort.
  • It feeds a crowd effortlessly and looks impressive even though it only takes an hour start to finish.
02 -
  • Do not skip the resting time after baking or the custard will be too loose and the casserole will fall apart when you serve it.
  • Whisk the béchamel constantly while adding milk or you will end up with lumps that are nearly impossible to smooth out.
  • Press the bread gently into the custard before baking so every slice soaks up the creamy mixture evenly.
03 -
  • Grate the Gruyère yourself instead of buying pre-shredded, it melts smoother and tastes infinitely better.
  • If your béchamel feels too thick, whisk in a splash more milk off the heat until it reaches a pourable consistency.
  • Let the eggs and milk come to room temperature before whisking so the custard blends more smoothly and bakes more evenly.
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