Hello again-
Actually, there would be no cooking involved whatsoever. Cats are the only true carnivores there are that are also domesticated pets. Ideally, their diet is a raw meat diet, and it's understandable if you don't want to deal with that type of diet for her. Basically, you mix the meat (ground beef, liver or other meat that you decide on), with the supplement - freeze it in individual servings - an icecube tray works beautifully, and thaw out the food in the morning. A couple of great positives for this type of diet is that there are no fillers, so there is VERY VERY little waste in the litter box. Cats use every bit of what they take in on this diet, so there is little output. Also, there is very little smell as this is what their body deems to be a perfect diet. You can go to www.felinefuture.com for more information on this if you decide to think about it. It takes about 10 minutes total to mix up once a week and is actually less expensive than commercial diets.
I can suggest if you don't want to go with this that you find a food for her that does not contain corn or corn gluten. Most cats that have problems with food allergies or diarrhea have problems with the fillers that are used in the foods. Putting her on rabbit or duck or lamb as the main protein source in her food may also help considerably, and there are several excellent products out there that contain those as the main portion of the diet. If you go to www.petfooddirect.com, you will find several 'natural' foods as well as many that do not contain corn or corn gluten. Wellness, Felidae, California Natural are just a couple that do not contain corn and if you look through the food lists, you will find many that have alternatives to fish or chicken as the main source of protein.
Please let me know if I can help further.
Feline Healthcare
16 yrs health care mgmt & issues relating to cats, reproductive issues and multicat environments