How to keep dog's food interesting?

My almost 7 year old Bichon has just had her bladder stones removed. The vet told us that they were going to prescribe a Hill's diet. Knowing what's in their food, I refused to feed my dog Hill's and I got Canidae Platinum for senior dogs. Now, my dog is used to being fed a variety of foods- she gets bored easily so every month or so I would gradually switch to a different food to keep her interested. But, I'm going to feed her Canidae and that's it. What are some things that I can add to her food to keep it fun? I already boil chicken and rice, and soak her kibble in chicken broth. Are there any others? She LOVES human food and will eat just about anything! Although money isn't a problem, I want it to be reasonable. And, no raw please! I live with my parents and they will not let any of my pets eat raw! Thanks for your (serious) answers!