In ancient times Jewish women set aside a small piece of dough, called challah, for the Temple priest (kohen) whenever they made bread. After the destruction of the Holy Temple in Jerusalem, Jewish women began to burn a small piece of dough (challah) whenever they made bread in remembrance of the priest’s portion. Over time, challah came to refer to the whole bread, rather than just the portion separated and burned. It is traditional, not mandatory, for challah bread to be a braided egg bread.
Here is the recipe!