I have four dogs, and, I'm not sure if this would be best for just a single animal, but...
I've tried several formulas, and my guys selected several of them !
I now have THREE types of food out 24/7, those being Beef, Sea and Foul formulas. They select which one they want that day, not all of them want the same, and may move between them in the same sitting. I can clearly see that they enjoy the variety.
I use only 4 and 5 star formulas, and you might find one which is acceptable to you via this link...
http://www.dogfoodadvisor.com/best-dog-foods/best-dry-dog-foods/