The manager told Reddit users to ask him anything about the sandwich firm and left a mixed review about the company.
Using the name SubwayworkerUK, the anonymous worker told users to avoid certain meats and revealed the secret menu option of ‘frozen cookie dough’.
The employee even advised people how they might be able to recreate the Subway taste at home.
A Subway spokesman said: “All Subway stores are independently owned and operated by franchisees.
“All stores have very strict procedures in place to ensure products are served safely and to customers' satisfaction and all suppliers are required to meet our high standards of food safety and product integrity.”
Earlier this month, Subway launched its Summer of Music with Pepsi, featuring award-winning Grime artist Stormzy.