INTRODUCTION

A sandwich is a food item, typically consisting of two or more slices of bread with one or more fillings between them, or one slice of bread with a topping or toppings, commonly called an open sandwich. Sandwiches are a widely popular type of lunch food, typically taken to work or school, or picnics to be eaten as part of a packed lunch. They generally contain a combination of salad vegetables, meat, cheese, and a variety of sauces or savoury spreads. The bread can be used as it is, or it can be coated with any condiments to enhance flavour and texture. They are widely sold in restaurants and cafes.
Bread has been eaten with any meat or vegetables since Neolithic times. For example, the ancient Jewish sage Hillel the Elder is said to have placed meat from the Paschal lamb and bitter herbs between two pieces of matzah (or flat, unleavened bread) during Passover. During the Middle Ages, thick slabs of coarse and usually stale bread, called "trenchers", were used as plates. After a meal, the food-soaked trencher was fed to a dog or to beggars, or eaten by the diner. Trenchers were the precursors of open-face sandwiches. The immediate cultural precursor with a direct connection to the English sandwich was to be found in the Netherlands of the 17th century, where the naturalist John Ray observed that in the taverns beef hung from the rafters "which they cut into thin slices and eat with bread and butter laying the slices upon the butter"— explanatory specifications that reveal the Dutch belegde broodje was as yet unfamiliar in England.
Initially perceived as food men shared while gaming and drinking at night, the sandwich slowly began appearing in polite society as a late-night meal among the aristocracy. The sandwich's popularity in Spain and England increased dramatically during the 19th century, when the rise of an industrial society and the working