Buttermilk chicken with roast white beans and olives

1. Fry the mushrooms in the oil in a large saucepan until golden, then drain on kitchen paper. In the same pan, gently fry the garlic, cut side down, until golden and fragrant, then add the onions and fry for 3–4 minutes.
2. Place the whole chicken in the saucepan, with half the mushrooms and half the sage, then pour over the chicken stock. Add more water if necessary so the chicken is completely submerged. Simmer over a low heat for 45 minutes to 1 hour, or until the chicken is cooked through.
3. Remove the chicken from the broth, cover with foil and set aside. Simmer the broth for 10 minutes, then remove the skin from the chicken.
4. Portion the chicken and shred the meat. Return the meat to the broth. Serve with the mushrooms, sage and sweet potatoes.