01 - Set air fryer temperature to 350°F and allow it to preheat for 3 minutes before cooking.
02 - Open refrigerated dough tube and separate into 4 individual triangles. Arrange on clean work surface with wide end closest to you.
03 - Spread a thin, even layer of Dijon mustard across each dough triangle if using mustard for added flavor.
04 - Place one slice of roast beef, one slice of ham, and one slice of cheese on the wide end of each triangle, slightly overlapping the meat.
05 - Starting from the wide end, roll each triangle toward the pointed end. Tuck in the sides as you roll to enclose the fillings completely.
06 - Position croissants in air fryer basket with seam side facing down. Space evenly to allow air circulation and prevent touching.
07 - Brush tops lightly with softened butter using a pastry brush for enhanced golden color and flavor. Skip if preferred.
08 - Cook at 350°F for 7-8 minutes until exterior turns deep golden brown and cheese is fully melted. Let rest 2-3 minutes before serving.