Name: Best-Ever Croque Monsieur Sandwich Recipe
Prep time: 20 min
Cook time: 25 min
Total time: 45 min
Cuisine: French
Ingredients: 1 ½ cups milk; 4 tablespoons unsalted butter; 1/4 cup flour; 1/4 teaspoon salt; 1/8 teaspoon ground nutmeg; 1/8 teaspoon white pepper; Pinch of cayenne pepper (optional); 8 slices 1/2-inch thick country-style sourdough bread or pan de mie; 6 ounces Gruyere cheese, thinly sliced; 6 ounces ham slices, preferably Black Forest; 2 tablespoons Dijon mustard; 4 tablespoons unsalted butter, divided; 2 tablespoons olive oil, divided; 3 ounces (¾ cup) Gruyere cheese, shredded; 1/4 cup Parmesan cheese, grated on microplane grater

There’s just something utterly satisfying about biting into the melty, crispy, and buttery layers of a classic French sandwich. This Best-Ever Croque Monsieur Sandwich Recipe brings that café charm right into your kitchen, with a rich béchamel sauce and perfectly toasted sourdough that will have you dreaming of Paris with every mouthful.

The image shows two small stacks of food on baking paper over a tray, each stack made of layers including a browned base, a middle layer of dark red color, and topped with a thick, golden-yellow melted cheese layer that is slightly browned in spots and oozing around the edges. The melted cheese has a smooth, creamy texture with some spots where it has cooked more, creating a slightly crisp look. The baking paper underneath has spots of browned melted cheese and other baked drips. The surface under the tray is a white marbled texture. photo taken with an iphone --ar 2:3 --v 7

Jump to:

Why You'll Love This Recipe
Ingredients & Why They Work
Make It Your Way
Step-by-Step: How I Make Best-Ever Croque Monsieur Sandwich Recipe
Top Tip
How to Serve Best-Ever Croque Monsieur Sandwich Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Best-Ever Croque Monsieur Sandwich Recipe

Why You'll Love This Recipe

I’ve made Croque Monsieurs a dozen different ways, but this version truly stands out. It’s the balance of creamy béchamel, nutty Gruyère, and crispy sourdough that makes it irresistible. Plus, it’s surprisingly simple once you get the béchamel down!

Classic yet approachable: This recipe honors tradition but keeps things straightforward enough for every home cook.
Rich, creamy béchamel: The star of the sandwich adds luscious depth that elevates every bite.
Perfectly toasted bread: The crispy edges contrast beautifully with the gooey melted cheese inside.
Great for any occasion: Whether it’s a casual lunch or an elegant dinner, it feels just right.

Ingredients & Why They Work

Every ingredient here plays a crucial role in building layers of flavor and texture. Using high-quality cheese and fresh bread really makes the difference—you’ll want something sturdy yet tender for that perfect grilled sandwich experience.

Flat lay of a small white ceramic bowl of fresh milk, a few cubes of pale yellow unsalted butter, a small white ceramic bowl of fine white flour, a small white ceramic bowl with a pinch of salt, tiny white ceramic bowls each containing ground nutmeg, white pepper, and cayenne powder, eight thick slices of rustic country-style sourdough bread, several thin slices of pale yellow Gruyere cheese, a few slices of pink Black Forest ham folded neatly, a small white ceramic bowl filled with smooth Dijon mustard, a small white ceramic bowl with golden olive oil, a small white ceramic bowl with shredded Gruyere cheese, a small white ceramic bowl with finely grated Parmesan cheese, all arranged in perfect symmetry on a clean white marble surface, soft natural light, photo taken with an iPhone, professional food photography style, fresh ingredients, white ceramic bowls, no bottles, no duplicates, no utensils, no packaging --ar 2:3 --v 7 --p m7354615311229779997

Milk: The creamy base for the béchamel; whole milk works best for richness.
Unsalted butter: Essential for making the roux and adding buttery depth.
Flour: Thickens the béchamel into that luscious, spreadable sauce.
Salt, nutmeg, white pepper, cayenne: These seasonings bring subtle warmth and complexity to the sauce.
Country-style sourdough bread: I love its sturdy crumb and tangy flavor—it holds up perfectly against the béchamel and melty cheese.
Gruyère cheese: This nutty, meltable cheese is indispensable for that classic Croque Monsieur taste and gooey texture.
Ham slices: Black Forest ham is my personal favorite for its smoky-salty bite, but any quality ham works well.
Dijon mustard: Adds a tangy kick that cuts through the richness.
Olive oil: Combined with butter for pan-frying to get the sandwich golden and crispy.
Parmesan cheese: Sprinkled on top for a sharp finish and beautiful crust.

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Note: You'll find the complete list of ingredients, along with their exact measurements, in the printable recipe card at the bottom of this post.

Make It Your Way

I love tweaking this recipe depending on my mood or what I have on hand. It’s flexible enough to handle little edits that still deliver big on flavor. You should feel free to play around too!

Variation: Sometimes I swap black forest ham with thinly sliced turkey or prosciutto for a different twist that’s just as delicious.
Dietary tweaks: For a lighter version, try whole wheat bread and use a bit less butter in the béchamel.
Seasonal changes: Adding a thin slice of ripe tomato or some caramelized onions inside adds amazing seasonal notes.

Step-by-Step: How I Make Best-Ever Croque Monsieur Sandwich Recipe

A close-up view of a grilled sandwich held by a woman's hand, showing two thick slices of toasted bread with a golden brown crust. Between the bread layers are multiple thin folds of pinkish ham with smooth melted yellow cheese melting over the edges and oozing slightly. The sandwich looks soft inside and crispy outside. Behind the sandwich, part of the other half sits on a white plate with a white marbled surface in the background. photo taken with an iphone --ar 2:3 --v 7

Step 1: Whisk Up That Silky Béchamel

Start by melting butter gently over medium heat, then whisk in the flour to make a smooth roux. Lower the heat and slowly add your milk in small batches while whisking constantly—this avoids lumps and builds that perfectly creamy béchamel. The sauce should thicken to the consistency of spreadable butter or pudding, not pourable liquid. Don’t rush it! Patience here means the whole sandwich melts together beautifully.

Step 2: Build Your Sandwich Layers

Lay out your bread slices, and slather half with that luscious béchamel. Next, add a generous layer of Gruyère, then fold the ham to fit snugly on top. Spread the Dijon mustard on that, add the remaining Gruyère, and top with the remaining bread slices, béchamel side down. This structure creates those irresistible layers that meld into cheesy heaven once cooked.

Step 3: Pan-Fry to Golden Perfection

Heat olive oil and butter in your skillet to create that perfect combo for crisping the bread. Cook each sandwich over medium heat for about 2 minutes per side, pressing gently to ensure even browning. The cheese might not be fully melted yet, but don’t worry—we’re just laying down a golden crust.

Step 4: Béchamel Topping and Finish in the Oven

Spread the remaining béchamel on top of each sandwich, then sprinkle a blend of shredded Gruyère and parmesan cheese. Pop them in a 400°F oven for 10-12 minutes until the cheese melts beautifully, then broil for 2-3 minutes to get that topping golden and slightly crispy. This final step seals the deal for the ultimate melt and flavor.

Top Tip

Making béchamel sauce can feel intimidating, but once you get the rhythm, it’s easy and rewarding. I honestly find it the key to transforming good sandwiches into something extraordinary.

Constant whisking: Prevents lumps and helps achieve that silky texture every time.
Slow milk addition: Adding milk bit by bit lets the sauce thicken gradually and keeps it smooth.
Get the thickness right: The béchamel should be thick enough to spread easily but not stiff like dough.
Reheat gently if needed: If the béchamel cools too much before topping, warm it with a splash of milk and whisk it just a bit to bring back that spreadability.

How to Serve Best-Ever Croque Monsieur Sandwich Recipe

Garnishes

I usually keep garnishes simple—a light sprinkle of fresh chopped parsley or a few cracked black peppercorns. It adds a fresh, herbal note that balances the richness beautifully. Sometimes, a small lemon wedge on the side can brighten flavors if you want a citrus touch.

Side Dishes

My go-to sides with this Best-Ever Croque Monsieur Sandwich Recipe are a crisp green salad dressed lightly with vinegar and a bowl of tangy tomato soup. The acidity cuts through the richness, making each bite more enjoyable. Roasted baby potatoes or seasoned fries also work great if you want something heartier.

Creative Ways to Present

For special occasions, I slice the sandwiches diagonally, arrange them on a wooden board with little ramekins of mustard and cornichons, and garnish with edible flowers or fresh herbs. It creates a classy, inviting spread that feels both rustic and elegant—perfect for brunch or intimate gatherings.

Make Ahead and Storage

Storing Leftovers

I wrap leftover sandwiches tightly in plastic wrap and keep them in the fridge for up to 2 days. This keeps the layers moist, but I don’t recommend storing them much longer or they might lose that crispy charm.

Freezing

Freezing works surprisingly well. I wrap sandwiches individually in foil and freeze up to a month. When ready to enjoy, I thaw overnight in the fridge and reheat in the oven to bring back that fresh-baked texture.

Reheating

Reheating croques in a toaster oven or regular oven at 350°F for 10-15 minutes helps restore the crisp bread and melty cheese. Avoid microwaving because it can make the béchamel and bread gummy. You want that crunch back!

Frequently Asked Questions:

Can I use a different cheese if I can’t find Gruyère?

While Gruyère is classic for its nutty flavor and great melting properties, you can substitute Emmental or a good-quality Swiss cheese. Just avoid very mild cheeses that won’t melt as nicely or overpower the béchamel.

What’s the secret to a smooth béchamel sauce?

Constant whisking and adding milk slowly bit by bit are key. Also, make sure you cook the roux long enough to remove any floury taste before adding milk. If the sauce gets too thick, a splash more milk can loosen it back up.

Can I make these sandwiches ahead of time?

Yes! You can assemble them entirely, cover tightly, and refrigerate for up to 24 hours before cooking. Just add a few extra minutes to the baking time to ensure the cheese is perfectly melted.

Is there a vegetarian option for this recipe?

Absolutely! Swap the ham for grilled vegetables like zucchini, eggplant, or mushrooms, and use a vegetarian Gruyère alternative if needed. The béchamel and cheese still provide plenty of flavor and richness.

Final Thoughts

This Best-Ever Croque Monsieur Sandwich Recipe is one I keep coming back to because it’s that perfect comfort food with an elegant twist. Whether you’re making it for a simple lunch or impressing guests, it’s guaranteed to delight. So grab your skillet, that trusty sourdough, and get ready to treat yourself—you won’t regret it!