Ham Gruyere Croissant Sandwich

How to Make Ham Gruyere Croissant Sandwich

1. 1

   Step 1: Preheat and prepare croissants

   Preheat your oven to 375°F (190°C). Split the croissants horizontally and spread softened butter evenly on the cut sides; place the bottoms on a baking sheet lined with parchment.

   For this step

   • 4 countLarge croissants (split)
   • 2 tbspUnsalted butter, softened
2. 2

   Step 2: Brush tops with egg wash

   Beat the egg until smooth and lightly brush the outside tops of the croissant halves (the pieces you’ll place on top) to promote a glossy, golden finish. Reserve a little egg wash for any spots that need touch-up before baking.

   For this step

   • 1 countLarge egg (for egg wash)
   
3. 3

   Step 3: Add mustard

   Spread about 1/2 tablespoon of Dijon mustard on each croissant bottom for a bright, savory layer. Be even so the mustard complements but doesn’t overpower the ham and cheese.

   For this step

   • 2 tbspDijon mustard
   
4. 4

   Step 4: Layer ham and Gruyère and bake

   Top each mustard-coated bottom with 2 slices of ham and roughly 2 ounces (about 56 g) of Gruyère. Place the top halves over the sandwich, then bake for 8–10 minutes until the cheese is melted and croissants are warmed through.

   For this step

   • 8 slicesSliced ham (Black Forest or your preference)
   • 8 ozGruyère cheese, sliced or shredded
   
5. 5

   Step 5: Finish with greens

   Remove sandwiches from the oven and open them slightly to add a small handful of fresh arugula to each (if using) so it wilts just a touch from the residual heat. This adds brightness and a peppery contrast.

   For this step

   • 1 cupFresh arugula (optional)
   
6. 6

   Step 6: Season and serve

   Sprinkle a pinch of flaky sea salt over the arugula or exposed cheese, close sandwiches, and serve immediately while warm and melty. These are best enjoyed fresh from the oven.

   For this step

   • 1/4 tspFlaky sea salt (to finish)
   

1. Preheat your oven to 375°F (190°C). Split the croissants horizontally and spread softened butter evenly on the cut sides; place the bottoms on a baking sheet lined with parchment.
2. Beat the egg until smooth and lightly brush the outside tops of the croissant halves (the pieces you’ll place on top) to promote a glossy, golden finish. Reserve a little egg wash for any spots that need touch-up before baking.
3. Spread about 1/2 tablespoon of Dijon mustard on each croissant bottom for a bright, savory layer. Be even so the mustard complements but doesn’t overpower the ham and cheese.
4. Top each mustard-coated bottom with 2 slices of ham and roughly 2 ounces (about 56 g) of Gruyère. Place the top halves over the sandwich, then bake for 8–10 minutes until the cheese is melted and croissants are warmed through.
5. Remove sandwiches from the oven and open them slightly to add a small handful of fresh arugula to each (if using) so it wilts just a touch from the residual heat. This adds brightness and a peppery contrast.
6. Sprinkle a pinch of flaky sea salt over the arugula or exposed cheese, close sandwiches, and serve immediately while warm and melty. These are best enjoyed fresh from the oven.