"Houses of Parliament" is the full form of HP in HP sauce. The dark sauce is well spiced and is widely used in a variety of recipes. It compliments beef stews, potatoes and bacon very well.
Its exact recipe is unknown, but experts claim it consists of a tomato base, smatterings of malt vinegar, generous amounts of dates, tamarind and rye flour. HP sauce became popular in Britain in1899. The sauce is manufactured by the Heinz company and is available in bottles of 255 to 600 grams.
The company's website claims that one in four households in Britain purchases HP sauce. The recipe was altered in 2011 in order to meet UK's sodium regulations; however, despite the alteration, its popularity has remained strong.