Heat oil in a pan. Cook chicken until browned and remove from pan and drain. Fry sausage for 1 minute or until just browned. Add onion and garlic to the pan and cook stirring for 1 minute. Add turmeric and rice to pan and cook for 1 minute until rice is coated with oil. Add stock and vegetables and season to taste . stir to combine well. Bring to a boil. Reduce the heat to low. Place the chicken on the rice and simmer covered for 15 minutes or until the liquid is absorbed and the rice is tender. Make sure to keep checking to ensure the rice does not stick to the base of the pan but do not uncover for too long. Add prawns in the last 5 minutes of cooking. Serve hot.