Remove the chicken from its packaging and lay it on a rimmed baking sheet. Pat chicken dry with paper towels. If the chicken comes with any internal organs such as the liver or neck, remove them from the cavity of the chicken. You can either cook them separately or discard them.
In a small bowl, stir together the garlic powder, dried parsley, paprika, and sea salt.
Drizzle the avocado oil (or olive oil) over the chicken and use your hands to rub it over the full surface, ensuring the entire chicken is coated with a light layer of oil. Sprinkle the spice blend over the outside of the chicken, then pat the seasonings into the flesh with your hands to ensure they stick.
If you have kitchen twine, secure the legs with a piece of kitchen twine so that they don't bow out during the cooking process.
Note: If you have the time, you can let the chicken sit in the refrigerator covered in spices for a few hours prior to cooking it in the slow cooker. This will allow the chicken to tenderize and makes for the most delicious chicken. If, however, you don't have the time, you can immediately proceed to cooking the chicken after seasoning it.
Transfer the chopped onion and carrots (and potatoes if adding) to the bottom of the slow cooker in an even layer. Pour in ½ cup of broth or water.
Place the seasoned chicken on top of the vegetables and secure the lid on the crock pot.
Slow cook on High heat for 3.5 to 4 hours, or until the internal temperature of the chicken reaches 165 degrees F. Or, slow cook on low heat for 6-8 hours. The exact cook time depends on the size of your chicken and its temperature going into the crock pot.
To verify the internal temperature, insert a meat thermometer into the thickest part of the breast (away from the bone) and wait until the numbers stop moving.
Transfer the chicken to a rimmed baking sheet (to catch any juices). If you'd like golden-brown crispy skin, broil the chicken in the oven for 4 to 8 minutes, or until the skin reaches your desired level of crisp. Let chicken rest for at least 10 to 15 minutes.
Slice the chicken using a sharp knife and serve with veggies and any additional sides.
