Remove any giblets from chicken and clean chicken.
Rub spice mixture onto the chicken.
Place in resealable plastic bag and refrigerate overnight. (I usually skip this step because I am always in a hurry).
When ready to cook, put chopped onion in bottom of crock pot.
Add chicken. No liquid is needed, the chicken will make it's own juices.
Cook on low 4-8 hours.
Note: I highly recommend a pop-up timer in the chicken because some crock pots cook faster/slower than others (my crock pot cooks this recipe in 4-5 hours).