Croque Madame Recipe

Make the roux

Warm the milk in a small saucepan or microwave until just warm (do not boil). In a medium saucepan over medium heat, melt 3 tbs unsalted butter. Add 3 tbs all-purpose flour and whisk constantly for 1–2 minutes until the mixture is smooth and lightly bubbling but not browned.

Finish béchamel

Slowly pour the warm milk into the roux in a thin stream while whisking continuously to prevent lumps. Continue whisking and cook over medium-low heat until the sauce thickens to a smooth, pourable consistency (about 4–6 minutes). Stir in 1 tbs heavy cream for richness, 1 tsp Dijon mustard, and 1 tsp freshly grated nutmeg. Season with salt and white or black pepper to taste.

Add truffle flavor

Remove from heat and whisk in 1 tsp white truffle oil and, if using, 1 tsp finely chopped black truffle or truffle paste. Taste and adjust seasoning. Keep the béchamel warm (cover lightly) while assembling sandwiches; if it thickens too much, whisk in a tablespoon of warm milk to loosen.

Preheat and prepare bread

Preheat oven to 425°F (220°C) and position a rack in the middle. Lightly butter one side of each of the 8 bread slices with the softened butter (this will be the outside).

Assemble sandwiches

Place 4 bread slices buttered-side down on a baking sheet. On each, layer 2 slices of ham (or enough to cover), then a generous sprinkle (about 1/4 cup) of grated Gruyère. Spoon about 3–4 tbs of the warm truffle béchamel over the cheese on each sandwich and spread to the edges. Top with the remaining bread slices, buttered-side up.

Grill briefly (optional stovetop)

For an extra crisp exterior, heat a skillet over medium heat and sear each assembled sandwich 1–2 minutes per side until golden, pressing gently with a spatula. Transfer back to the baking sheet.

Bake with béchamel and cheese

Spoon an additional 2–3 tbs of béchamel over the top of each sandwich, then evenly distribute the extra 1 cup grated Gruyère over them. Place the baking sheet in the oven and bake 6–8 minutes until the cheese is melted and starting to bubble. To get a golden gratinéed top, switch the oven to broil and broil 1–2 minutes more while watching carefully so it does not burn.

Fry eggs

While sandwiches bake, heat 1 tbs butter or neutral oil in a nonstick skillet over medium heat. Crack eggs into the skillet and cook until whites are set but yolks remain runny for classic Croque Madame (about 2–3 minutes). For over-easy, gently flip and cook an additional 20–30 seconds. Season with salt and pepper to taste.

Keep warm

Keep fried eggs warm in a low oven (about 200°F / 90°C) on a plate covered loosely with foil if the sandwiches finish before the eggs.

Remove baked sandwiches from oven. Place one fried egg on top of each sandwich. Scatter optional chopped chives over the eggs and serve immediately while hot and the yolk is runny so it mixes into the béchamel and melted cheese when cut.