Season the chicken generously with salt and pepper. Over high heat in a casserole dish, Add the oil and sear the chicken on all side until coloured.Add the rest of the ingredient to the casserole dish.If using the slow cooker, Place in the slow cooker bowl, the onions, carrots, quartered lemons, chilli, garlic, rosemary, corn flour mixture, the milk and chicken stock.Add the chicken and season well with salt and pepper.
Cover with the lid and cook for 1hour 45 minutes in the oven or for 4-5 hours on low in a slow cooker. Check if the chicken is cooked through.Carve the chicken either in the slow cooker / casserole or on a board.Serve immediately with potato and a generous serving of the infused vegetable and sauce.