Creating Baked Ham and Cheese Croissants can be a fun and simple process if you follow these steps:

1. Preheat Oven: Preheat your oven to 375°F (190°C).
2. Prepare Croissants: Slice the croissants in half lengthwise without cutting all the way through.
3. Add Mustard: If using, spread a thin layer of Dijon mustard on the bottom half of each croissant.
4. Layer Ham: Place two slices of ham on the bottom half of each croissant.
5. Add Cheese: Top the ham with one or two slices of cheese, depending on your preference.
6. Close Croissants: Gently fold the top half of the croissant over the filling.
7. Brush with Butter: Use a pastry brush to apply melted butter on top of each croissant for a golden finish.
8. Bake: Place the filled croissants on a baking sheet and bake for 20-25 minutes or until the cheese is melted and the croissants are golden brown.
9. Garnish: If desired, sprinkle fresh herbs on top before serving.
10. Serve Hot: Remove from the oven and serve warm.

These steps will guide you in creating these incredible croissants effortlessly.