Quick Recipe Version (TL;DR)
Quick Ingredients
- 4 tbsp unsalted butter, divided
- 2 tbsp all-purpose flour
- 1 3/4 cups whole milk, warmed
- 1/2 tsp kosher salt; pinch white pepper; 1/8 tsp freshly grated nutmeg
- 8 slices thick-cut pain de mie or country white bread
- 2–3 tbsp Dijon mustard
- 8 oz thinly sliced Parisian ham
- 6 oz Gruyère, coarsely grated (about 1 1/2 cups)
- 1 oz Parmesan, finely grated (about 1/4 cup), optional
- Chives for garnish; cornichons and extra Dijon for serving
Do This
- 1. Heat oven to 425°F (220°C). Line a sheet pan with foil and set a rack inside. Warm the milk.
- 2. Make béchamel: melt 2 tbsp butter, whisk in 2 tbsp flour 1 minute, then whisk in warm milk. Simmer 3–5 minutes until spoon-coating thick. Season with salt, white pepper, and nutmeg.
- 3. Lightly brush both sides of bread with 2 tbsp melted butter; toast on the rack 4 minutes, flipping halfway.
- 4. Spread Dijon on 4 slices. Layer 2 oz ham and half the Gruyère. Top with remaining bread.
- 5. Spoon 2–3 tbsp béchamel over each top; sprinkle remaining Gruyère and Parmesan.
- 6. Bake 10–12 minutes until hot and melty; broil 1–3 minutes until deeply golden.
- 7. Rest 2 minutes, shower with chives, and serve with cornichons and extra Dijon.
Why You’ll Love This Recipe
- Classic French comfort with accessible steps and pantry-friendly ingredients.
- Silky, nutmeg-kissed béchamel that won’t turn grainy or thin.
- Smart bake-then-broil method for bubbling tops and crisp, non-soggy bread.
- Restaurant-level results in about 40 minutes, start to finish.
Grocery List
- Produce: Fresh chives (or flat-leaf parsley) for garnish
- Dairy: Whole milk, unsalted butter, Gruyère, Parmesan (optional)
- Pantry: Thick-cut white bread (pain de mie or country loaf), Dijon mustard, all-purpose flour, ground or whole nutmeg, white pepper, kosher salt, black pepper, Parisian ham (deli), cornichons (optional)
Full Ingredients
Béchamel Sauce
- 2 tbsp (28 g) unsalted butter
- 2 tbsp (16 g) all-purpose flour
- 1 3/4 cups (420 ml) whole milk, warmed
- 1/2 tsp kosher salt
- Pinch white pepper (or black pepper)
- 1/8 tsp freshly grated nutmeg
Sandwiches & Assembly
- 8 slices thick-cut pain de mie or country white bread
- 2 tbsp (28 g) unsalted butter, melted or very soft (for brushing bread)
- 2–3 tbsp Dijon mustard
- 8 oz (225 g) thinly sliced Parisian ham
- 6 oz (170 g) Gruyère, coarsely grated (about 1 1/2 cups)
- 1 oz (28 g) Parmesan, finely grated (about 1/4 cup), optional for extra browning
For Serving
- Fresh chives or parsley, finely chopped
- Cornichons and extra Dijon
- Freshly ground black pepper
Step-by-Step Instructions
Step 1: Preheat and prepare your pan
Heat the oven to 425°F (220°C). Line a rimmed sheet pan with foil for easy cleanup and set a wire rack on top (this keeps the undersides crisp). Position an oven rack in the middle, with the broiler available for later.
Step 2: Warm the milk
Warm the milk in a small saucepan over low heat or microwave it in a heatproof cup until steaming, about 60–90 seconds. Warm milk blends smoothly into the roux, preventing lumps in your béchamel.
Step 3: Make the béchamel (silky, not stodgy)
In a medium saucepan over medium heat, melt 2 tbsp butter. Whisk in the flour and cook, whisking constantly, for 1 minute to remove raw flour taste. Slowly pour in the warm milk, whisking constantly to avoid lumps. Bring to a gentle simmer and cook 3–5 minutes, whisking, until thick enough to coat the back of a spoon. Season with 1/2 tsp salt, a pinch of white pepper, and the nutmeg. Cover the surface with a piece of parchment or plastic wrap to prevent a skin and keep warm over very low heat.
Step 4: Lightly toast the bread
Brush both sides of each bread slice with the melted/softened butter. Arrange on the rack and toast in the oven for 4 minutes total, flipping halfway. You’re aiming for lightly dried and barely golden—this helps prevent sogginess once sauced.
Step 5: Build the sandwiches
Spread 1/2–3/4 tsp Dijon on one side of 4 slices. Layer 2 oz ham over each, then divide half of the Gruyère on top. Cap with the remaining bread slices and press gently to compact. Optional but decadent: swipe 1 tablespoon béchamel inside each sandwich before closing.
Step 6: Smother with sauce and cheese
Spread 2–3 tablespoons béchamel over the top of each sandwich, going right to the edges. Sprinkle with the remaining Gruyère and a light dusting of Parmesan for extra browning and frico-like crunch.
Step 7: Bake, then broil for color
Bake at 425°F (220°C) for 10–12 minutes, until the centers are hot and the cheese is melted. Switch the oven to broil (high). Move the pan so the sandwich tops sit about 6 inches (15 cm) from the heating element. Broil 1–3 minutes, watching closely, until the tops are deeply golden and bubbling.
Step 8: Rest, garnish, and serve
Let sandwiches rest 2 minutes to set. Shower with chopped chives and a few grinds of black pepper. Serve immediately with cornichons and extra Dijon alongside.
Pro Tips
- Warm milk makes a lump-free béchamel; add it slowly while whisking.
- Grate cheese from a block—pre-shredded won’t melt as smoothly.
- Use day-old bread or lightly toast fresh slices to prevent sogginess.
- Don’t oversauce—2–3 tbsp béchamel per sandwich top is plenty for coverage and browning.
- Broilers vary: keep the oven door ajar and watch like a hawk for perfect color.
Variations
- Croque Madame: Top each sandwich with a sunny-side-up or over-easy egg just before serving.
- Mornay Twist: Whisk 1/2 cup grated Gruyère into the béchamel to make a classic Mornay sauce.
- Provençal: Add thin slices of ripe tomato inside the sandwich with the ham, then proceed as directed.
Storage & Make-Ahead
Béchamel can be made up to 3 days ahead; refrigerate with plastic wrap pressed directly on the surface. Rewarm gently with a splash of milk if thick. Assemble sandwiches (without béchamel and cheese on top) up to 4 hours ahead; wrap and refrigerate. Top and bake when ready, adding 2–3 extra minutes to the bake time if starting cold. Leftovers keep 2 days in the fridge; reheat on a rack at 350°F (175°C) for 10–12 minutes, then broil 30–60 seconds to re-crisp. Freezing is not recommended.
Nutrition (per serving)
Approximate values: 700 calories; 36 g protein; 39 g fat (22 g saturated); 44 g carbohydrates; 1,250 mg sodium.
