Mix 100ml of chicken stock, crushed garlic, rosemary, pepper and salt. Peel onion and place it inside the chicken's cavity. Then pour in half the mixture and tie the legs together with white thread. Pour remaining half of the mixture on chicken, some Worcestershire sauce and hot sauce on the chicken and spread evenly. Leave to marinate for 2-3 hours.
Preheat oven to 200 degree Celsius Put chicken on a baking tray together with the marination and add some water. Put small chunks of butter on chicken. Then Place in oven and reduce temperature to 180 degrees Celsius.
Turn chicken when golden brown on one side. Leave to cool after taking it out from the oven for minutes and then debone the chicken. Collect the juice from the baking dish.