Preheat oven to 200 degrees celsius or 392"F
Peel and chop the carrots. Chop up the celery into about 3 pieces. Smash the 4 garlic cloves, you can leave the skin on
In a bowl mix the soft butter, minced garlic, chopped thyme, salt and pepper. Set aside
Place the chicken one flat surface and pat it dry with paper towels. Be sure to remove the giblets from inside, you won't need this. Gently lift the skin off the chicken, the breast side only, starting at the bottom of the chicken. You can use a dessert spoon or a butter knife. I used a butter knife and it worked well.
Rub the butter mixture underneath the skin, be generous. Rub the remaining butter all over the chicken, this will now be on top of the skin
Pop the lemon and the half bunch of thyme inside the chicken
Tie the drumsticks with some food safe string. Tuck the tips of the wings underneath the chicken.
In a baking pan place the carrots, onion, celery and garlic. Place the chicken on top, breast side facing up. Sprinkle the chicken spice on top and drizzle the olive oil
Pour the chicken stock or broth around the chicken
Place the pan in the oven and bake at 200 degrees celsius for 1 hour and 10 minute, basting at least twice with juices from the pan. After 20 minutes each time. Chicken is ready when the juices run clear. You can make a little prick between the drumstick and body of the chicken
The celery can be discarded but the other veggies can be eaten. Allow the chicken to rest for at least 10 minutes before cutting it up. Serve with the remaining liquid from the pan