Name: Gooey Croque Monsieur Sandwiches 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 oz. Gruyere cheese, thinly sliced; 6 oz. ham slices, preferably black forest; 2 tablespoons Dijon mustard; 4 tablespoons unsalted butter, divided; 2 tablespoons olive oil, divided; 3 oz. (¾ cup) Gruyere cheese, shredded; 1/4 cup Parmesan cheese, grated

There’s something irresistibly comforting about a warm, cheesy sandwich with crisp golden bread and melty insides—this Gooey Croque Monsieur Sandwiches Recipe hits all those notes perfectly. It’s the kind of dish that makes you close your eyes with each bite and think, “Wow, I have to make this again.”

Two baked slices stacked with layers of light golden melted cheese on top, the cheese is bubbly and slightly browned at edges with a creamy texture spread unevenly. Beneath the cheese, there are visible layers of browned slices and a round, slightly charred base, all placed on crinkled white baking paper on a baking tray. The surface underneath has 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 Gooey Croque Monsieur Sandwiches Recipe
Top Tip
How to Serve Gooey Croque Monsieur Sandwiches Recipe
Make Ahead and Storage
Frequently Asked Questions:
Final Thoughts
Gooey Croque Monsieur Sandwiches Recipe

Why You'll Love This Recipe

I still remember the first time I made Croque Monsieur at home—it felt like an elegant French bistro experience without leaving my kitchen. What makes this Gooey Croque Monsieur Sandwiches Recipe stand out is its perfect balance of creamy béchamel, nutty Gruyère, and smoky ham, topped with an irresistibly crispy golden crust. You’re not just making a sandwich; you’re crafting a little slice of heaven.

Melty Cheese Bliss: The combination of sliced and shredded Gruyère ensures every bite oozes gooey goodness.
Rich Béchamel Sauce: A creamy, spiced white sauce that adds depth and keeps the sandwich moist and luxurious.
Crispy Crunch: Toasted sourdough gets beautifully crisped in butter and olive oil for that golden finish.
Simple, Yet Impressive: This recipe is straightforward enough for a weeknight but elegant enough to wow guests.

Ingredients & Why They Work

All these ingredients come together so harmoniously. The béchamel’s creamy texture pairs beautifully with the nutty Gruyère and the savory, slightly smoky ham. Picking good quality bread and cheese will make a noticeable difference, so keep an eye out for fresh sourdough and authentic Gruyère at your deli.

Flat lay of fresh country-style sourdough bread slices arranged neatly, thinly sliced pale yellow Gruyere cheese, folded pink Black Forest ham slices, whole clean unshelled brown eggs, small white ceramic bowls containing golden unsalted butter cubes, fine white flour, creamy white milk, smooth Dijon mustard, golden olive oil, finely shredded Gruyere cheese, finely grated pale Parmesan cheese, small white bowls with ground white pepper, ground nutmeg, fine salt, and a small pinch of bright red cayenne powder, all ingredients balanced symmetrically 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: For the béchamel base, the milk adds creaminess and moisture to balance the sandwich.
Unsalted Butter: Melts perfectly for the roux and the skillet sear without overpowering the other flavors.
Flour: Thickens the béchamel to a rich, spreadable consistency.
Salt: Essential for seasoning and highlighting the cheese’s nutty notes.
Nutmeg, White Pepper, Cayenne: These spices add a subtle warmth and complexity—cayenne is optional but gives a nice little kick.
Country-Style Sourdough Bread: The sturdy texture holds up well to the béchamel without getting soggy and crisps up beautifully.
Gruyère Cheese: The star player—mild, nutty, and melts like a dream. Use sliced for layering and shredded for topping.
Ham (preferably Black Forest): Adds smoky, savory depth and a nice contrast to the creamy béchamel.
Dijon Mustard: Adds a tangy, sharp note that cuts through the richness.
Olive Oil: Combined with butter for pan-frying to get that golden-brown crust without burning.
Parmesan Cheese: Grated finely over the top—it adds a delicious salty crust after baking and broiling.

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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 experimenting with this Gooey Croque Monsieur Sandwiches Recipe to suit the mood or season. Whether you swap the ham for smoked turkey or add a touch of fresh herbs into the béchamel, it’s all about making it your own. Don’t be afraid to play around—you’ll discover new favorite versions along the way.

Variation: Sometimes I add a sprinkle of fresh thyme or a tiny bit of Dijon mixed into the béchamel for an herby twist—super delicious!
Vegetarian Option: Swap ham for grilled mushrooms or caramelized onions to get that savory richness without the meat.
Spicy Kick: Adding a pinch more cayenne or a dash of hot sauce to the béchamel gives the sandwich a nice wake-up call.
Different Bread: While I love sourdough, pan de mie or rustic white bread work well too; just pick something sturdy enough to hold the sauce.

Step-by-Step: How I Make Gooey Croque Monsieur Sandwiches Recipe

A close-up view of a sandwich held by a woman's hand, showing three layers: the top and bottom layers are thick, toasted bread slices with a golden-brown crust and soft, airy inside; the middle layer has thin slices of pink ham folded neatly; between the bread and ham, melted yellow cheese drips slightly, stretching and covering parts of the ham and bread. In the background, part of the sandwich is placed on a white plate on a white marbled surface, with melted cheese spreading around it. The lighting is bright, making the textures of bread, cheese, and ham very clear. photo taken with an iphone --ar 2:3 --v 7

Step 1: Make the Velvety Béchamel Sauce

Start by melting the butter over medium heat for the roux, then stir in the flour and cook for a couple minutes to get rid of the raw flour taste. Off the heat, whisk in the milk in small batches—this part takes a little patience, but it’s so worth it when you get that perfectly smooth sauce. Add the salt, nutmeg, white pepper, and if you’re feeling adventurous, just a pinch of cayenne. Bring it back to a simmer and whisk until it thickens nicely—think spreadable butter or thick pudding texture. It should be smooth and glossy, not runny.

Step 2: Slather the Bread and Layer the Sandwich

Lay out 8 slices of your bread on a baking sheet lined with parchment. Spread half the béchamel thickly on every slice—don’t be shy here, it forms that signature creamy layer. Then top four of those slices with half the Gruyère followed by all the ham slices. Spread Dijon mustard over the ham for that classic tang, top with the remaining Gruyère, and close the sandwiches with the béchamel side down, creating a little béchamel “seal.”

Step 3: Pan-Fry to Golden Perfection

Heat olive oil and butter together in a skillet over medium heat. The olive oil helps prevent burning while the butter adds flavor and richness. Grill the sandwiches in batches for about 2 minutes per side, pressing down gently with a spatula to get an even crust. The cheese inside might not be fully melted yet—that’s okay because we’ll finish it in the oven.

Step 4: Top and Bake to Gooey, Golden Goodness

Spread the remaining béchamel on top of each sandwich—if it’s cooled and thickened too much, just warm it gently and whisk with a splash of milk to loosen it up. Sprinkle the shredded Gruyère and Parmesan on top, then pop them in a 400°F oven for 10-12 minutes until melty. For the best golden crust, broil for 2-3 minutes—but keep a close eye so it doesn’t burn. Serve piping hot with a knife and fork to savor every gooey bite.

Top Tip

This recipe has become one of my go-to comfort foods, especially on chilly evenings. After making it a few times, I found these tips really make the difference between good and unforgettable.

Perfect Béchamel Consistency: Don’t rush the whisking; adding milk in small increments helps avoid lumps and builds a silky smooth sauce.
Toast in Butter and Olive Oil: This combo browns the bread beautifully while keeping things from burning—trust me, I’ve scorched more than one sandwich in butter alone.
Use Fresh Gruyère: Slicing from a block and shredding fresh gives such better melt and flavor than pre-shredded bags.
Broil at the End: The final broil adds that irresistible golden crust, but watch closely because it goes from perfect to burnt in seconds.

How to Serve Gooey Croque Monsieur Sandwiches Recipe

Gooey Croque Monsieur - Serving Suggestion

Garnishes

I usually keep garnishes simple—a sprinkle of fresh parsley adds a touch of color and freshness. Sometimes a few baby arugula leaves on the side brighten up the plate with their slight bitterness, balancing the richness perfectly.

Side Dishes

Classic French fries or crispy roasted potatoes are my favorite sides. A simple green salad with vinaigrette cuts through the richness nicely, while a small bowl of tomato soup turns it all into a cozy meal. You can never go wrong with seasonal roasted veggies either.

Creative Ways to Present

For a special brunch or gathering, I’ve stacked Mini Croque Monsieurs on a platter with toothpicks holding them together, making it easy for guests to grab. Adding a drizzle of honey mustard or a side ramekin of Dijon gives a fun dip option. Fancy, but so simple.

Make Ahead and Storage

Storing Leftovers

I wrap leftovers tightly in foil or airtight containers and refrigerate. They keep well for up to 2 days, but the crust won’t stay as crispy. Still, reheated properly, they taste almost as good as fresh.

Freezing

This sandwich freezes pretty well if you wrap it tightly and freeze on a baking sheet first, then transfer to a freezer bag to avoid sticking. When I thaw and reheat, the béchamel might be a bit softer, but the flavor remains fantastic.

Reheating

I reheat leftovers in a 350°F oven on a parchment-lined pan, uncovered, for about 10-15 minutes to crisp the crust again and warm the cheese all the way through. A quick broil at the end revives that beautiful golden topping.

Frequently Asked Questions:

What makes a Croque Monsieur different from a regular grilled cheese?

A Croque Monsieur is more than just grilled cheese; it includes layers of ham, a creamy béchamel sauce, and Gruyère cheese, then finishes with a gratinéed top, giving it a richer, more complex flavor and texture.

Can I make this recipe dairy-free or vegan?

While traditional Croque Monsieur relies on butter, milk, and cheese, you can adapt it by using plant-based butter, milk alternatives, and vegan cheese. However, the béchamel and the melty cheese experience will differ from the classic version.

Is it necessary to use Gruyère cheese?

Gruyère is preferred for its nutty flavor and meltability, which define Croque Monsieur. You can substitute with other Swiss-style cheeses like Emmental, but avoid ones that don’t melt well.

How do I avoid the sandwich getting soggy?

Spreading the béchamel thickly and toasting the sandwich in a butter and olive oil pan helps develop a crisp crust, preventing sogginess. Using sturdy bread like sourdough also helps keep the sandwich from falling apart.

Final Thoughts

This Gooey Croque Monsieur Sandwiches Recipe is one of those dishes I return to whenever I want something warm, cheesy, and indulgent. It’s deceptively simple but delivers complex flavors and textures that feel truly special. I hope you enjoy making (and eating!) it as much as I do—once you try this, your sandwich game will never be the same.