Heat oven Fan 180C/200C/Gas 6. Drizzle your chicken with a little olive oil and rub into the skin. Season well with plenty of salt and pepper. Cut the lemon in half and place both pieces inside the chicken. Sit in a roasting tray and cook in the oven for 1 hour and 15 minutes. When the chicken has finished it’s cooking time, remove from the oven and leave to rest before cutting. Reserve the lemony cooking juices.
Meanwhile, prepare your vegetables for the lentils. Set to one side whilst you sit down and relax for a while.
When the chicken has just 5 minutes left of cooking time, you can start your lentils. Heat the olive oil in a large frying pan and add the onion to soften. After 3 minutes, add the bacon pieces. Add some black pepper. Now add the courgette and fry all together for a few minutes. Then add the garlic and the lentils and tomatoes. Season well and fry until everything is cooked, just a few minutes.
Pour in some of the reserved cooking juices from the chicken, just enough for the lentils to become lovely and oozy but not soupy. Add the parsley and stir through.
Place a big pile of lentils on a plate and top with a roasted chicken breast. Drizzle with a tablepoon of the chicken juices.