Croque Monsieur Casserole (Print Version)

Buttery bread layered with ham, Gruyère, and creamy béchamel sauce baked to golden perfection for brunch or dinner.

# What You'll Need:

→ 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

# Step-by-Step Guide:

01 - Preheat oven to 375°F. Lightly butter a 9x13-inch baking dish.
02 - In a medium saucepan, melt 2 tablespoons butter 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 3-4 minutes. Season with nutmeg, salt, and pepper. Remove from heat.
03 - Butter one side of each bread slice. Arrange half the bread slices, buttered side down, in the prepared baking dish.
04 - Top bread with half the ham slices and half the Gruyère cheese. Repeat with remaining bread (buttered side down), ham, and cheese.
05 - 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.
06 - Pour béchamel sauce over the top and spread evenly across the surface.
07 - Bake uncovered for 35-40 minutes until puffed, golden brown, and bubbling at the edges. Allow to rest 10 minutes before serving.

# Top Tips:

01 -
  • It delivers all the crispy, cheesy, creamy magic of a Croque Monsieur without flipping a single sandwich.
  • You can assemble it the night before and bake it fresh in the morning while everyone is still half asleep.
  • The béchamel on top turns golden and bubbly, creating a crust that cracks under your spoon like crème brûlée.
  • Leftovers reheat beautifully and somehow taste even richer the next day.
02 -
  • Press the bread gently into the custard after pouring or the top slices will stay dry and float instead of soaking through.
  • Don't skip the resting time after baking, or the custard will run everywhere when you cut into it.
  • If your béchamel gets lumpy, take it off the heat and whisk hard, or strain it through a fine mesh sieve.
03 -
  • Grate your own Gruyère instead of buying pre-shredded, it melts smoother and tastes infinitely better.
  • Use day-old bread if you have it, it holds up better to the custard without turning to mush.
  • If the top is browning too fast, tent it loosely with foil for the last 10 minutes of baking.
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