HP Sauce is a British brown sauce, the main ingredients of which are tomatoes and tamarind extract. It was named after London’s Houses of Parliament. After making its first appearance on British dinner tables in 1899, HP Sauce went on to become an icon of British culture. The bottle I purchased was manufactured in The Netherlands and distributed out of London. I am not a huge steak fan but I decided to try the sauce on some steak and prime rib.