My 18 1/2 yr. dog,KidneyDisease,hungry!Are green beans "safe"?What else is ok?

[VIOLET0019]

My darling dog, that I rescued 18 1/2 yrs. ago, was diagnosed with KidneyDisease, when they did the blood workup prior to her dental cleaning(approx. 1 1/2 yrs.ago). Since then I am feeding her canned food, from the Vet, (a rip off,ridiculously expensive) specifically for Kidney Disease, lower protein and phosphorus. She is hungry all the time, probably due to not getting enough protein! I would appreciate any suggestions for "extras" that are safe to give her in between meals. i.e. are cooked organic green beans ok, sweet potato? carrots? Also, as she does not like these special canned foods, that I reluctantly purchase at the Vet - I give her variations of the canned Royal Canin Mature Consul, Hill's Prescription Diet K/D Lamb and also Chicken. She does not enjoy any of them. So I have found a way to entice her to eat, I cook chicken and mix in at every meal - 2 tbsp. of shredded chicken with quite a bit of water. Sometime I will smother the canned food, for her Kidney Disease, with the flavour of 1/2 tsp. cat food mixed into a lot of water, mixed in to her canned food. She used to enjoy eating ....this food must taste horrible if she doesn't want to eat it. I would appreciate any advice, suggestions of any cooked vegetables that I can give her that are low in protein, and anything else that is safe? I give her 1/2 tsp. of apple each day. Is plain porridge safe? Help please? Thank you very much! Woof Woof