Try mixing the chicken, carrots or peas in with the dry kibble.  Warm it up first and mix it up well.   
You can also try adding some canned food to his kibble; I like the Wellness 99% canned meat; they make beef; lamb, turkey; chicken . .  I warm this up too if it's been in the refrigerator.   
Lucy loves buttered noodles mixed in with her kibble; the occasional cottage cheese, green beans, plain, unseasoned chicken broth and chicken . . .     
				__________________   Mommy to Lucy, Ringo, and Matthew       |