If you have a slow cooker, this can be prepared in the morning and left to cook all day. It will be ready for supper and needs nothing more than some mashed or baked potatoes or some couscous or rice and a side of green vegetables. If not using a slow cooker, preheat the oven to gas 2, 150°C, 130°C fan.

Combine the butter with the crushed garlic, oregano and a seasoning of salt and pepper. Then starting at the cavity end, gently ease the skin away from the chicken across the breast and spread the butter under the skin, pressing down on the skin to spread it out. Rub the top of the chicken skin with some salt and pepper. Bruise the whole garlic and put it in the cavity of the bird.

Spread the onion out in the base of the slow cooker. Alternatively, if cooking the chicken in a conventional oven, use a large, lidded casserole or a sturdy roasting tin.

Sit the chicken on top of the onions, breast-side up. Pour the stock in and cover with the slow cooker or casserole lid (if using a roasting tin, cover with two layers of foil, sealing the edges tightly). If using a slow cooker, turn it to high for 45 minutes then reduce it to low. Leave the chicken to cook for 8-10 hours, until very tender.