Couple of days ago, I cut some holes in small cardboard boxes (for teabags), to make them feeding mazes for the cats.
They do try to get everything in their bowl, by begging. But, once they give up, they really have a ball attacking the little boxes. Funny to see and hear. Luna, picking the box up and ferociously shaking it is the most effective hunter for food pellets.
And Sirius is not overeating anymore. I can already notice the difference in how fast the cat-food finishes in just a few days.