I'm sort of full of myself today. We are snowed in--can't go anywhere because ice is covering several inches of snow. So, I pulled out two frozen chicken carcasses (from two rotisserie chickens) and a package of frozen uncooked chicken wings. I wedged them into my 6 qt PC, added filtered water and started the cooking process. The frozen birds delayed the PC coming to pressure, but when it did finally, I timed the cooking for 30 minutes. I made sure to have the heat just hot enough to produce gentle pressure. And the result was lovely golden chicken broth.
I picked some chicken off the recooked carcasses, and added veggies, and made soup. Lovely soup.
I've always had probs making broth from roasted chicken carcasses, and I thought perhaps adding uncooked wings to the pot might make a better flavored broth. I was right! I bought a family pack awhile ago and froze them in packs of three to add to chicken carcasses for broth.