Preheat oven 180°c. Rinse the chicken and pat dry.
Season the cavity and skin with salt.
Place the chicken in a large food storage bag.
Combine the salad dressing with the juice of 1 lemon and pour the mixture into the bag with the chicken. Seal and refrigerate for 30 minutes, or up to 8 hours.
Blitz the rosemary, thyme, sage, shallot, garlic, ½ teaspoon salt, pepper, and olive oil in a food processor.
Let sit while the chicken is marinating (at least 30 minutes, or up to 8 hours).
Remove the chicken from the marinade, discard the marinade, and pat the chicken dry with paper towels.
Insert the remaining whole lemon into the cavity of the chicken.
Rub the herb oil mixture generously over the top of the chicken.
Place the chicken in the oven for around 1 hour 15 minutes, or until cooked and juices run clear. Timings will depend on the size of the chicken.
Let the chicken sit for 5 minutes, remove the lemon from the cavity, and serve