1. Bring your child and your cat together in the same location. This is easy to do if there's food available, or even just the vague promise that there might be food for at least one of them.
2. Let the child pick up a shiny object. Today, Caitlyn chose a can opener. Let the child do random things with said shiny object. For example, open and close the can opener in a sideways position. Experiment with putting can opener handles on either side of a can or jar.
3. Let the cat choose a position on the other side of the counter from the child. This is easy if you have a stool and the cat is accustomed to sitting on it when you cook, perhaps out of some delusion that some of that food might be destined for his dish. Wasabi begs indiscriminately.
4. As long as there is a light source above and behind the child with shiny object, a light spot will appear on the ceiling above and behind the cat. This will cause the cat to look frantically up at the ceiling, chattering at the flickering spot.
The cat's behavior will cause the child to realize she's created a light spot that interests the cat. The child will then adjust her random movements with the shiny object to more directly get a response from the cat.
This is a potentially infinite loop, at least in our house. I suppose at some point the cat might recognize the light spot on the ceiling as being unattainable or the child might get bored or realize her post-school cereal is getting soggy, but around here, this game only ends at the request of the present adult.