My Coco loves anything pureed so i sometimes feed him a bit of oatmeal, cooked with water and a bit of honey or pureed carrots and potatoes (or whatever i have on hand) with a bit of water and sweetened with honey. He usually gobbles it up like he has never eaten before.
I also sometimes cook a mixture of barley, wheat, white rice and mixed vegetables for him or give him a dry mix of bran, oatmeal and flaxseeds. I hope this helps!