Place the sliced onion into the bottom of your crockpot. Top the onions with the boneless skinless chicken breasts.
Pour over the chicken broth, followed buy the beer – or more chicken broth if that’s what you’re using.
Mix the seasonings together in a bowl and then sprinkle them over the chicken breasts, pressing the seasoning down into the chicken to adhere better.
Cover and cook on low for 6 hours. Shred chicken and then let it cook in the juices in the crockpot on low for 30 minutes to an hour before serving.