In a small bowl, add the olive oil, salt, pepper, garlic powder, minced onion, paprika, and ground mustard. Mix everything until all the ingredients are well combined.
Place the vegetables in the bottom of the slow cooker, add the chicken, rosemary, and parsley on top. Rub the chicken with the spice mixture.
Cover and cook on high for 4 hours or low for 8 hours, or until the chicken is fully cooked (the internal temperature should reach 165°F) and the chicken flesh pulls away easily from the bone.
Transfer the chicken to a baking sheet and broil it in the oven for a few minutes until golden brown, if desired. Transfer the chicken to a serving plate with the vegetables and serve.
Notes
If you are using a frozen chicken, make sure that the chicken is completely thawed before you cook it. This will help it cook evenly.
The chicken will release a lot of juices as it cooks. You can remove some of the excess liquid halfway through cooking if desired.
You can make a sauce to go with the chicken. Try a simple BBQ sauce or honey mustard glaze.
Chicken and vegetables will keep in an airtight container in the refrigerator for up to four days.
See my tips and tricks for making this Slow Cooker Whole Chicken above the recipe box.