Pre-heat the oven to 180C/375F (160C fan). Place all of the vegetables, olive oil and herbs inside the Bakewell Oven Bag.
Give them a good shake to ensure they're evenly coated.
Place the chicken inside the bag on top of the vegetables and position on your roasting tray.
Seal the bag with the provided tie and cut a small piece off one corner of the bag - this will allow steam to escape and ensure a tasty skin.
Roast for approximately 80 minutes until well cooked. If you put a skewer into the thickest part of the meat, the juices should run clear (no pink tinge). If you have a meat thermometer it should read at least 165F (75C) at the thickest part of the meat.
Allow the chicken to sit for 10 minutes, then cut open the bag. You can then lift the chicken out of the bag, taking care to drain the juices back into the bag.
Lift the bag and tip the veg into a colander over a pan to catch the juices. You can then dish up the vegetables.
Make the gravy
You can now use all of the lovely chicken and veg juices to make an amazing gravy. Place the pan over a medium heat. Add a little boiling water if you want to stretch the quantity a little further.
Mix 1 tbsp of cornflour with a little cold water and add to the pan.
Stir over the heat until thickened, season to taste, then transfer to a gravy boat and serve