No, you really don't want to cook the meat because it destroys the taurine which is an essential amino acid for them. They'll eventually die if they don't get it. I think most cat foods add it in after the cooking.

I grind or chop up chicken thighs, turkey meat, ground beef. Give occassional tuna. Some people are fanatically against giving cats tuna, but from what I've read, it is fine as long as it isn't their entire diet.

For supplements I have tried adding my own vitamins, like vit E, but they get turned off to the taste. So I found some cat vitamins at my pet store and I'm giving them that.

There's people that grind up the bones too, they call it BARF (bones and raw food). However, you need to be around when you pet is eating it in case they choke on a bone. Anyway, the bones are good for their gums (to chew on) and gives them calcium.

My grinder wouldn't handle the bones so we skip that and I powder up one of my calcium pills for them and mix it into their food. I give them largish chunks of chicken periodically so they have to chew it like crazy. Hope that gives them a good gum work-out.