Cut the carrots into large batons and halve the onion. Cut one half into large slices, then arrange the sliced onion and carrot batons on the bottom of the slow cooker to form a rack for the chicken. Stuff the other half of the onion and a clove of garlic into the cavity of the bird.
In a separate bowl combine all of the ingredients for the rub with the oil, then smear all over the chicken. Place the chicken in the slow cooker on top of the vegetables and press the remaining two cloves of garlic in between the breast and the legs.
Pour the chicken stock into the slow cooker, taking care not to wash the rub off of the chicken. Use enough stock to just cover the chicken wings (see the picture for reference).
Cook on low for 2 to 3 hours. The chicken is cooked when the juices run clear, and the leg pulls away easily from the body. We recommend using a meat thermometer, see the recipe notes for more info.
Once cooked, transfer the chicken to a roasting tray and grill (broil) under a high heat for approximately 5 minutes until the skin turns golden brown. Serve immediately!
Notes
How much stock to use?
The volume of stock will vary according to the size of the chicken and slow cooker model used. We used 1L (4.5 cups) of stock in a 6.5L slow cooker, with a 1.6kg (3.5lb) chicken. The liquid should come up to the wings of the chicken.
How long will it take to cook?
For best results use a meat thermometer (see the equipment list for a recommendation). Insert the thermometer in between the breast and thigh, ensuring you don't touch the bone. When the chicken is cooked the internal temperature will reach 75°C (165°F) and the juices will run clear. Once you remove the chicken from the slow cooker this may continue to increase a little - this is fine! As a guide, if your slow cooker has a metal pot then the cooking times will likely be closer to two hours. Slow cookers with ceramic pots take longer to heat, and therefore cooking will take longer.