Brown sauce was a condiment. Vicki Pallister painstakingly added it to the programming of the First Doctor's food machine because Barbara Wright favoured it. (AUDIO: 1963)
The Ninth Doctor would have called ketchup his favourite sauce if not for the fact that he could not "look brown sauce in the eye again." He made use of both sauces while at a cafe with Rose Tyler. (AUDIO: Retail Therapy)
Sergeant John Benton was also fond of brown sauce. (AUDIO: Time Tunnel)