Croque Monsieur Casserole (Printable)

Buttery bread layered with ham, Gruyère, and béchamel sauce baked until golden and bubbling for an elegant brunch.

# What You'll Need:

→ Bread & Dairy

01 - 12 slices white sandwich bread, crusts removed
02 - 3 tablespoons unsalted butter, softened
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 Make It:

01 - Preheat oven to 375°F. Lightly butter a 9 by 13 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 1.25 cups milk, stirring constantly, until thickened and smooth, approximately 3 to 4 minutes. Season with nutmeg, salt, and pepper. Remove from heat and set aside.
03 - Butter one side of each bread slice. Arrange half the bread, buttered side down, in the prepared 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, 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.
07 - Bake uncovered for 35 to 40 minutes, or until puffed, golden, and bubbling at edges. Let rest 10 minutes before serving.

# Expert Advice:

01 -
  • It tastes like the best sandwich you've ever had, but you only have to assemble it once and let the oven do the work.
  • The creamy béchamel soaks into every layer, creating pockets of richness that make each bite feel indulgent.
  • You can prep it the night before and bake it fresh in the morning for brunch without any stress.
  • Leftovers (if there are any) reheat beautifully and somehow taste even better the next day.
02 -
  • Press the bread gently into the custard before baking, or you'll end up with dry spots that didn't soak through and a soggy bottom layer.
  • Let the casserole rest after baking, because cutting into it too soon will cause the custard to run and you'll lose that beautiful structure.
  • If your béchamel starts to get lumpy, pull it off the heat and whisk hard, or blend it smooth with an immersion blender.
03 -
  • Use day-old bread if you have it, because it soaks up the custard without getting too soggy or falling apart.
  • Grate your own Gruyère instead of buying pre-shredded, because freshly grated cheese melts smoother and tastes infinitely better.
  • Taste your béchamel before you pour it over the casserole and adjust the seasoning, because this is your last chance to get it right.
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