Croque Madame: The French Brunch That's Easier Than It Sounds

The béchamel is the heart of this sandwich, and it comes down to two things. First, cook your butter and flour together for a full 90 seconds before adding any milk — you're looking for a pale, slightly biscuity smell, which tells you the raw flour taste is gone. If you rush this step, the sauce will taste starchy no matter how much cheese you add. Second, once the milk is in and the sauce starts to thicken, keep it at a gentle simmer for a full two minutes. The starch needs that time to fully set — pull it too early and the sauce will loosen up the moment it hits the heat of the assembled sandwich. Add your Gruyère and Parmesan off the heat, whisk until smooth, season with salt, pepper, and just a tiny pinch of nutmeg, then cover and keep warm. That's your sauce done.

These three ingredients are doing a lot of work together. Gruyère and ham share a deep, savory richness that makes them feel like they were made for each other — and in a lot of ways, they were. The mustard is the secret weapon: spread a thin layer on each slice of toasted bread and it cuts right through the richness of the béchamel, brightening the whole bite and making the ham taste more like itself. Don't skip it, even if you're not a big mustard person. The egg on top pulls everything together — when that yolk breaks, it becomes a second sauce that softens the saltiness of the ham and cheese and ties the whole plate into one cohesive, incredibly satisfying bite.

The classic version is hard to beat, but there's plenty of room to play. If you want to lean into the French bistro vibe, swap the regular sliced ham for a good-quality cooked ham with some visible texture — it holds up better under the sauce and has more presence in the sandwich. For the bread, brioche or a thick-cut country loaf gives you a richer base and toasts up beautifully. If you want to go meatless, skip the ham entirely and layer in some sautéed mushrooms — they bring that same deep savory note and soak up the béchamel like a dream. And if you're cooking for a crowd, assemble the sandwiches ahead of time, spoon the sauce on top, and run them under the broiler for 2–3 minutes until everything is bubbling and golden.

Let's be real — this is a rich, satisfying brunch dish, not a light salad. Each serving comes in around 760 calories with a solid 46 grams of protein, which means it'll keep you full well into the afternoon. The dairy load is real (hello, béchamel), and the sodium is on the higher side thanks to the ham and cheese — so if you're watching salt, look for a lower-sodium ham at the deli counter. There's no added sugar to worry about. What's missing from the plate is vegetables and fruit, so if you're building a full brunch spread, a simple green salad or some fresh fruit on the side rounds things out nicely and balances the richness.