Preheat the oven to 200°C (400°F).
Place the whole chicken in a deep-sided roasting pan so it fits snugly.
In a mixing bowl combine the chicken stock, lemon juice, chopped oregano, chopped parsley, crushed garlic and Dijon mustard; whisk until blended.
Pour the herb and lemon sauce over the chicken and into the cavity, allowing the liquid to surround the bird.
Drizzle the olive oil over the chicken, then season generously with salt and pepper.
Roast the chicken uncovered for about 1 hour 30 minutes, starting breast-side down; halfway through cooking flip the chicken breast-side up and baste with pan juices so the underside becomes golden and the top crisps.
Check the chicken is cooked through (juices run clear and an internal temperature of 75°C / 165°F in the thickest part), then remove from the oven and rest briefly.
Spoon the pan juices over the chicken to serve as a sauce.