Pebete

A pebete is an Argentine and Uruguayan soft oval bun made of wheat flour with a thin brown crust, rather like a fatter hot dog roll. It is often used to make a sandwich, typically filled with cheese, cured meat, tomato and mayonnaise; the sandwich itself is usually called pebete followed by its filling, e.g., pebete de queso . According to the Royal Spanish Academy it is from the lunfardo term for young boy, itself from Catalan pevet.

Source: Wikipedia