Divide the croissant dough into 3 pieces and roll each out into a rectangle 12-inches by 4-inches. Cut each into 12 triangles (for the salted caramel pecan, you can do pain au chocolate style cuts), and score and fill with each of the 3 combinations, rolling up into croissant shapes. Place these on a parchment-lined baking tray, leaving 2-inches between them and cover them with a tea towel and then plastic wrap. Let the croissants rise for 90 minutes.
Preheat the oven to 190°C. Brush the croissants with the eggwash, sprinkle the ham & cheese croissants with a little sesame seed and then bake for 12 to 15 minutes, until they are a rich golden brown.
The croissants are best enjoyed the day they are baked. If you wish to prepare ahead, you can make the dough, fold it and let it rise, and then cut and shape the croissants. Freeze the filled and shaped croissants on a baking tray (freezing not suggested for the peanut butter banana style), then pack in a container. The croissants should fully thaw and proof for about 3 hours before then baking.