Go Back
Croque Madame

Croque Madame Recipe

A French bistro-style sandwich made with crisp buttered sourdough, savory ham, Dijon mustard, melted Gruyère, creamy mornay sauce, and a freshly fried egg.
Print Recipe Pin Recipe
Prep Time 10 minutes
Cook Time 25 minutes
Total Time 35 minutes
Course Main Course
Cuisine French
Servings 2
Calories 1395 kcal

Equipment

  • Small saucepan
  • Whisk
  • Large nonstick or cast-iron skillet
  • Rimmed baking sheet
  • Flexible egg spatula
  • Cheese grater
  • Measuring cups and spoons
  • Small bowls for cracking the eggs
  • Broiler-safe oven setup

Ingredients
  

For the Gruyère Mornay Sauce:

  • 1 tablespoon unsalted butter
  • 1 tablespoon all-purpose flour
  • 1 cup whole milk
  • 1 ounce Gruyère cheese freshly shredded
  • Freshly ground black pepper to taste
  • Kosher salt if needed

For the Sandwiches:

  • 4 thick slices sourdough bread approximately 1/2 inch thick
  • 2 tablespoons unsalted butter softened
  • 2 teaspoons Dijon mustard
  • 4 slices deli ham or Black Forest ham
  • 2 ounces Gruyère cheese freshly shredded

For the Fried Eggs:

  • 1 tablespoon unsalted butter
  • 2 large eggs
  • Kosher salt to taste
  • Freshly ground black pepper to taste

Instructions
 

  • Prepare the ingredients before beginning. Shred the Gruyère, separate the ham slices, measure the milk, and arrange the bread on a clean work surface.
  • Make the mornay sauce. Melt 1 tablespoon butter in a small saucepan over medium heat.
  • Add the flour and whisk continuously until it forms a thick, bubbling paste, approximately 30 to 60 seconds. Do not allow the flour to brown deeply.
  • Slowly pour in a small amount of the milk while whisking continuously until smooth.
  • Gradually add the remaining milk, continuing to whisk and scraping the bottom and corners of the saucepan.
  • Increase the heat to medium-high and bring the mixture just to a boil while stirring constantly.
  • Reduce the heat to medium-low and simmer, stirring regularly, until the sauce thickens enough to coat the back of a spoon, approximately 1 to 2 minutes.
  • Remove the saucepan from the heat.
  • Stir 1 ounce shredded Gruyère into the sauce until completely melted and smooth.
  • Season with freshly ground black pepper. Taste before adding salt because the Gruyère and ham are already salty.
  • Cover the saucepan and keep the mornay warm over very low heat while assembling the sandwiches.
  • Spread one side of each sourdough slice with 1/2 tablespoon softened butter.
  • Arrange the bread buttered-side down on the work surface.
  • Spread 1 teaspoon Dijon mustard over each of two bread slices.
  • Spread approximately 2 tablespoons warm mornay sauce over the mustard on each slice.
  • Top each prepared slice with 2 slices ham and 1 ounce shredded Gruyère.
  • Close each sandwich with one remaining bread slice, keeping the buttered sides facing outward.
  • Preheat the oven broiler to high and position an oven rack approximately 6 inches below the heating element.
  • Place the sandwiches in a large skillet over medium heat.
  • Toast for 2 to 3 minutes per side, pressing only lightly if needed, until both sides are golden and the cheese inside begins to melt.
  • Transfer the toasted sandwiches to a rimmed baking sheet.
  • Spread approximately 1/4 cup warm mornay sauce over the top of each sandwich.
  • Place the baking sheet beneath the broiler.
  • Broil for 1 to 2 minutes, watching constantly, until the sauce is bubbling and develops light golden-brown spots.
  • Remove the sandwiches from the oven and transfer them to serving plates.
  • Carefully crack each egg into a separate small bowl.
  • Wipe out the skillet and melt the remaining 1 tablespoon butter over medium heat.
  • Gently slide the eggs into separate sides of the skillet.
  • Season lightly with kosher salt.
  • Cook undisturbed until the whites are set and the yolks reach your preferred doneness, approximately 3 minutes for a soft yolk.
  • For firmer whites without flipping, cover the skillet briefly during the final portion of cooking.
  • Season the eggs with freshly ground black pepper.
  • Use a flexible spatula to place one fried egg on top of each sandwich.
  • Serve immediately while the sandwiches, mornay sauce, and eggs are hot.

Notes

Freshly grated Gruyère produces a smoother mornay sauce than most pre-shredded cheese.
Comté, Emmental, Fontina, Jarlsberg, or mild Swiss cheese can replace Gruyère.
Use thick, sturdy sourdough or white country bread. Bread with very large holes may allow the sauce to leak through.
Add the milk gradually while whisking to reduce lumps in the mornay sauce.
If the mornay becomes too thick, whisk in a small splash of milk.
Toast the sandwiches over medium heat so the bread does not burn before the cheese warms.
Watch the broiler continuously. The sauce can go from bubbling to burned very quickly.
Cook and broil the sandwiches before frying the eggs so both tasks receive your full attention.
Leaving off the egg turns the sandwich into a Croque Monsieur.
For a softer or runny yolk, consider using pasteurized shell eggs. FDA guidance recommends cooking eggs until both the yolk and white are firm.
Store leftover sandwiches without the fried egg in an airtight container in the refrigerator for up to three days.
Store leftover mornay sauce separately and reheat gently with a small splash of milk.
Nutrition is estimated and will vary with the bread, ham, cheese, butter, sauce portion, and egg preparation.