Place a roasting rack inside a large tray. The rack should lift the chicken from the base of the tray.
Pat the chicken dry with paper towels. In a small bowl, combine and mix all the ingredients for the dry marinade. Using your hands, rub the dry marinade all over the chicken, including in its cavity. Place the chicken on top of the rack and tray and place in the fridge uncovered for at least 2 hours or overnight.
Before roasting, remove the chicken from the fridge and leave it at room temperature for 1 hour. In the last 15 minutes of the chicken resting, preheat the oven to 230°C (450°F) or 210°C (410°F) for fan-forced ovens.
For the garlic bread stuffing - Roughly tear the bread into little pieces and place them in the food processor, then pulse until large crumbs form. Add the salt and mixed herbs into the crumbs. In a frying pan, melt the butter over medium heat, then place in the garlic. Stir the garlic for 30 seconds or until fragrant, but don't let it burn. Add the breadcrumbs into the butter and stir regularly for 2 minutes. Place stuffing into a small bowl and set aside for later.
Line the base and sides of a large baking tray with baking/parchment paper, then place foil over the top, as this will make cleaning up much easier. Place the garlic, onion, carrots and celery on top of the foil and drizzle 1 tablespoon of oil over the vegetables.
Pat the chicken with paper towels but don't rub off the spices. Wipe the cavity from the marinade so the stuffing won't be too salty. Using a spoon, fill in the chicken's cavity with the stuffing. Brush the chicken all over with the remaining olive oil, then tie the chicken legs together. Place the chicken over the vegetables with the breast side up, then tuck its wings behind it.
Place the chicken into the oven, then reduce the oven temperature down to 200°C (390°F) or 180°C (360°F) for fan-forced ovens. Bake the chicken for 90 minutes (1.5 hours) or adjust the roasting time based on the weight of your chicken. It's approximately 20 minutes more or less in the oven for every 500g/1 lb or insert a thermometer into the inner thigh area near the breast. It should read 75ºC (165ºF). Allow the chicken to rest for 15 minutes before carving.
Notes
(NOTE 1) Whole Chicken - I used free-range chicken that weighed 1.7kg (3.7lb), however, you can use any size chicken desired. You'll just need to adjust the baking time accordingly to the weight of your chicken. It's approximately 20 minutes more or less in the oven for every 500g/1 lb or insert a thermometer into the inner thigh area near the breast. It should read 75ºC (165ºF).(NOTE 2) Dried spice marinade - Mix your favourite dried herbs or spices together. I used garlic powder, thyme, sage and smoked paprika.(NOTE 3) Coarse salt - Avoid using table salt or fine salt as it'll make the chicken very salty. I used coarse Kosher Salt, their grains are the right size and not too big. (NOTE 4) Day-old bread - I used day-old sourdough for the garlic bread filling. However, any variety of day-old bread should work. Day-old bread is drier and not as soft as fresh bread, which makes it easier to turn into breadcrumbs in the food processor. Dried bread also absorbs more liquid than fresh bread.(NOTE 5) Vegetable trivet - This is a selection of vegetables used as a bed for the chicken to lie on when baking. The vegetables impart flavour to the chicken whilst roasting. Use the leftover roasted vegetables for sauce or gravy. I used garlic, onion, celery, and carrots.Leftovers - Allow chicken to cool completely at room temperature, then transfer into a sealed container and refrigerate. It'll be good for up to 3 to 4 days.