Mixing raw and cooked?

I am to the end of raw meat that I ordered from Hare Today and I realized I am a little short on boneless meat to dilute a chicken mixture with. I will need to go ahead and mix the new mixture up before I can get a new order in from Hare Today. I figured I could try getting some ground boneless chicken from Whole Foods, but everything I've read says not to use raw meat from grocery stores. I need an additional one pound of boneless to add to a 5 pound mix. I'm wondering if it would be okay to cook the one pound of grocery store meat and mix it in with the remaining five pounds of raw from Hare Today?

Anyone have opinions/advice?

Why not go with chunks instead? Just buy meat you can chunk up and add that. If you wanted to go with cooked you could, but i wouldn't mix it together I'd mix it at serving time only. 

Is chunked meat safer than ground meet? I thought the freshness of the meat was the issue, but is it that grinding exposes it to more germs?

If doing chunked meat, how small should the chunks be for kitties that are just used to ground?

Raw meat from the supermarket or butcher shop is fine as long as the meat has not been enhanced or seasoned with anything (broth, spices, sodium solutions, vinegar, herb extracts, etc) and you do not buy pre-ground meat. Pre-ground meat may have bacteria mixed throughout it beause you don't know how clean the store grinders are. It's better to buy whole cuts of meat and chop or grind if yourself. Or just cook pre-ground supermarket meat (no oil or anything) and add to the bowl at serving time, freezing extras for later use. I would not mix raw and cooked meats together and freeze the entire batch.

Kittens have pretty small mouths so chunks of meat should be fairly small to be easily eaten. A fine mince should be good.

That makes sense—thank you for the answers! I don't have a meat grinder so I think I'll just go with a small dice.

It is very important to ensure that a cats diet is minimally processed as possible. Check for some recipes at Ctainfo.org. My cats have been eating raw food for almost 2 years now and absolutely fine by the grace of God.

Easy.  Buy a boneless meat from the grocery store, then cut it up with scissors or put it through a food processor.  I cut meat with scissors into decent size chunks, but I had to train my cats to eat the chunk without regurgitating.   You probably want to start small, e.g. size of your pinky fingernail.

I suggesting getting whatever looks freshest, but you have lots of options.  Gizzards, hearts, boneless chicken thighs or breast are good.  You could go a bit adventurous and try something new:  beef or lamb stew, turkey meat (I buy drumsticks and ask the butcher to peel the meat off the bone for me), even duck, quail, goat, or rabbit if you can find it and it's affordable.

There's a thread somewhere on raw feeding resources - lots of good tips there.  I do prefer to source my cats' food from Hare Today because it's much fresher than what's in the store, but grocery is a perfectly good option for shortfalls, and some members feed from groceries exclusively.