No, beef is not served in Mecca.
Based on the provided reference, the consumption of beef is prohibited in Mecca and Medina.
Specifically, the reference states:
"The holiest sites of Islam are Mecca and Medina where cow slaughter is not allowed and, therefore, selling gosht is prohibited."
This directly indicates that due to the prohibition of cow slaughter in these holy cities, you will not find beef ('gosht' is a term often used for red meat) being served or sold.
Therefore, the answer to whether beef is served in Mecca is a definitive no.
