Preheat the oven to 425 degrees F. Grease the bottom of your roasting pan with olive oil.
Remove the inside of the chicken (the giblets) and place it upside down (thighs up) into a roasting pan.
In a small bowl, mix 2 teaspoons of course sea salt, 1 teaspoon of ground black pepper, 1 teaspoon of thyme, and 1 teaspoon of rosemary together. Put a sprinkle of the seasoning mix inside of the chicken (in the cavity). Rub the rest of the seasoning onto the outside of the chicken.
Add 1 clove of garlic to the chicken cavity and put the rest in the pan surrounding the chicken. Add the sliced onion to the pan as well.
Squeeze one piece of the lemon into the chicken cavity and then put the lemon piece into the cavity. Take the second piece of lemon and squeeze the lemon juice into the pan with the garlic and onion. Take the third piece of the lemon and slice into thinner slices. Place on top of the chicken.
Put the pieces of parsnip, mushrooms, and carrots around the chicken.
Evenly pour 2 Tablespoons of olive oil onto the the veggies surrounding the chicken. Sprinkle 1 teaspoon of thyme onto the veggies.
Spray the chicken with an olive oil or greasing spray.
Cover the chicken with aluminum foil and cook for 1 hour and 15 minutes. Remove the cover and cook for another 15-30 minutes, until the chicken is cooked through.
The chicken will be done when you can cut between the leg and the thigh and only clear juices come out. It also is considered done if it reaches an internal temperature of at least 165 degrees F.