The first time I made this, I thought, “How fancy can a ham-and-cheese sandwich really be?” Reader, I was wrong. I scorched the top under the grill, forgot to season the sauce, and used supermarket sliced ham that tasted like regret. But once I slowed down and treated each step with care—hello Dijon, buttery grilled bread, thick cheesy sauce—it became one of my go-to quick comforts.
This isn’t a Tuesday sandwich. This is a put-the-kettle-on-and-pretend-you’re-in-Paris sandwich.
WHY THIS ONE WORKS SO WELL
- Two textures of cheese: Melted inside and bubbling on top. It’s a cheese lover’s dream.
- Toasted buttered bread: Crisps up golden on one side, stays soft on the other. The perfect bite.
- Punchy Dijon: Don’t skip it. It cuts through the richness and makes everything pop.
- Gruyère: Melts like a dream and has real flavour—not just bland goo.
Most recipes throw cheese on top and call it a day. This one doubles down with a silky cheese sauce you make fresh—and it’s worth it.
INGREDIENTS + WHY THEY MATTER
- White bread (4 slices) – Medium thickness is best. Too thin and it collapses, too thick and it dominates.
- Butter (50g) – Half for brushing bread, half for the sauce. Gives richness and golden colour.
- Dijon mustard (2 tbsp) – Adds zing. If you’re not a fan, use less—but don’t leave it out.
- Smoked ham (4 slices) – Thinly sliced, good quality. Adds depth without overpowering.
- Gruyère (100g) – Coarsely grated. Melts beautifully, doesn’t go stringy.
- Plain flour (15g) – Thickens the sauce.
- Full-fat milk (150ml) – Hot milk blends smoothly and speeds things up.
- Nutmeg (pinch) – Just a whisper. Don’t overdo it. Optional, but lovely.
- Salt + pepper – Essential. Taste your sauce and don’t skimp.
WANT TO CHANGE IT UP? HERE’S HOW
- No Gruyère? Emmental or Comté work well. Even a strong cheddar will do in a pinch.
- No ham? Use cooked turkey, or skip the meat and add wilted spinach or mushrooms for a veggie twist.
- Going posh? Add a fried egg on top and make it a Croque Madame.
- Bread swap? Sourdough or brioche slices can be stunning—just toast them a bit longer.
MISTAKES I’VE MADE (AND HOW TO AVOID THEM)
| What Went Wrong | Why It Happens | How to Fix It |
|---|---|---|
| Burnt top | Grill too hot, too close | Use medium heat + watch like a hawk |
| Lumpy sauce | Added milk too fast | Whisk slowly, bit by bit |
| Soggy bottom slice | Bread too soft or under-toasted | Use firmer bread + toast one side only |
| Cheese slid off | Sauce too thin | Let it thicken before topping |
HOW TO MAKE MARY BERRY’S CROQUE MONSIEUR
PREP THE GRILL
Preheat to medium. Line a tray with foil.
TOAST THE BREAD
Melt half the butter. Brush one side of each bread slice. Grill buttered side up for 1–2 mins till golden.
ASSEMBLE THE SANDWICHES
Flip slices over. Spread unbuttered side with Dijon. On two slices, layer ham + half the cheese. Top with other bread slices (golden side up).
MAKE THE CHEESE SAUCE
Melt remaining butter in a pan. Stir in flour. Gradually whisk in hot milk. Stir until thickened. Off heat, add nutmeg + 25g cheese. Season to taste.
TOP + GRILL
Spread sauce over sandwich tops. Sprinkle with remaining cheese. Grill 5 mins until golden and bubbling.
COOL + SERVE
Let sit 1 min before slicing—the cheese sets slightly and makes it easier to eat.
TIPS FROM MY KITCHEN
- I always toast just one side of the bread so the inside stays soft and melds with the cheese.
- Use a microplane for the nutmeg—you only need a few shavings.
- If making for a crowd, prep the sauce ahead and assemble sandwiches just before grilling.
- I freeze extra cheese sauce in a little tub for quick lunchtime toasties.
STORAGE + SERVING
- Fridge: Cooled leftovers keep in the fridge up to 3 days.
- Freezer: Wrap tightly in foil, freeze for 1 month. Thaw overnight in fridge.
- Reheat: Oven at 180°C (350°F) for 10–15 mins. Microwave works but softens the bread.
- Serve with: Green salad, cornichons, or tomato soup on the side.
FREQUENTLY ASKED QUESTIONS
Q: Can I make the cheese sauce ahead of time?
A: Yes—store in the fridge and reheat gently before using. Whisk if it separates.
Q: Can I skip the grill and use the oven?
A: Yep, bake at 200°C (180°C fan) for 10 mins instead. Not quite as crisp, but still delicious.
Q: What’s the difference between Croque Monsieur and Madame?
A: The Madame has a fried egg on top. The Monsieur is all about that cheese sauce.
Q: Can I use pre-sliced cheese?
A: You can, but it won’t melt or mix into the sauce quite the same. Grating is better here.
Try More Recipes:
- Mary Berry Eggy Bread Avocado and Ham Sandwich
- Mary Berry Smoked Salmon Canapé Sandwiches
- Mary Berry Pan Fried Falafel
- Mary Berry Breakfast Burrito UK Recipe
Mary Berry Croque Monsieur
Course: BreakfastCuisine: French-InspiredDifficulty: Easy2
servings7
minutes10
minutes800
kcalA gloriously golden ham-and-cheese sandwich topped with creamy Gruyère sauce and grilled until bubbling. Perfect for lunch, brunch, or whenever you fancy a bit of Parisian comfort food.
Ingredients
50g butter
4 medium white bread slices
2 tbsp Dijon mustard
4 thin slices smoked ham
100g Gruyère cheese, grated
15g plain flour
150ml hot full-fat milk
Freshly grated nutmeg
Salt + pepper to taste
Directions
- Preheat grill to medium. Line tray with foil.
- Melt half the butter, brush bread on one side, and grill that side until golden.
- Flip, spread mustard on unbuttered side. Layer ham and half the cheese on two slices. Top with remaining bread.
- Melt rest of butter, stir in flour. Gradually whisk in hot milk until thick. Remove from heat, stir in nutmeg, 25g cheese, salt + pepper.
- Spread sauce on top of sandwiches, sprinkle with remaining cheese. Grill until bubbling and golden.
- Let rest 1 min. Slice + serve immediately.
Notes
- I once used pre-shredded cheese—regretted it instantly. It clumps instead of melting smooth.
- Don’t skip the Dijon, even if you’re unsure. It adds contrast to the richness.
- If your sauce is too thin, just cook it a little longer over medium heat—it thickens quickly.