Preheat the oven to 400 degrees.

Place the chicken in a large casserole. Peel and cut onion, peel garlic, wash and cut lemon. Stuff chicken cavity with onion garlic and lemon.

Add avocado oil, lemon juice, salt and pepper in a small bowl. Mince garlic, rosemary, thyme and sage and add to the sauce. Mix well. Rub the whole chicken with the herb sauce.

If you want to add vegetables like leeks, onion, sweet potatoes etc. into the casserole for a side dish or to make gravy, cut the vegetables and add now.

Roast the chicken for 30 minutes. Take it out lift the chicken up and pour the juice from the chicken into the pan. If it is a lot of juice use it to baste the chicken. If not use 1 tbsp avocado oil to baste.

Lower the temperature to 350 degrees and place the chicken on the lowest rack in the oven for another 40 - 60 minutes. You can add roasted vegetables to the oven at this point on the highest rack. Baste every 15-20 minutes.

Check if it is done. Cooking time will vary depending on how big your chicken is and what kind of oven you have. Insert a meat thermometer into the chicken breast and make sure it doesn't touch the bone. The temperature should read 165 Degree Fahrenheit (75 degrees Celsius). If you don't have a thermometer cut into the meat and observe the meat and juices. The meat should be white and firm, the juices should be clear, not pink.

If you want to add more crispiness to the chicken change the temperature to broil and broil for the last 10 minutes until the skin is browned and crispy.