#625's special skill has always been making sandwiches... until Leroy and Stitch, when he successfully repairs a space shipwreck and gets it off the ground. Making a sandwich or any other snacks is sometimes called fixing a sandwich, etc.
In the movie, Stitch is sentenced to exile on an asteroid. In "The Asteroid", Stitch and co. travel to an asteroid to destroy it, only to find it inhabited by a lone alien. Now we have an idea about how he got there.