Creating Baked Ham and Cheese Croissants is straightforward if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Prepare Baking Sheet: Line a baking sheet with parchment paper to prevent sticking.
3. Unroll Croissant Dough: Carefully unroll the croissant dough on a clean surface. Separate the triangles.
4. Add Mustard (Optional): If desired, spread a small amount of Dijon mustard on each triangle.
5. Layer Ham and Cheese: Place a slice of ham and a slice of cheese on the widest side of each triangle.
6. Roll Croissants: Starting from the wide end, roll the dough towards the pointed end, ensuring the filling is enclosed.
7. Place on Baking Sheet: Arrange the rolled croissants on the prepared baking sheet, leaving space between each one.
8. Prepare Egg Wash: In a small bowl, whisk the egg until well combined. Brush the egg wash over each croissant for a golden finish.
9. Bake: Place the baking sheet in the preheated oven and bake for 12-15 minutes, or until the croissants are golden brown and crispy.
10. Cool Slightly: Once baked, remove from the oven and let cool for a few minutes before serving.

These steps will guide you in creating these incredible croissants effortlessly. Enjoy the delightful aroma that fills your kitchen as they bake!