Just before 8 p.m., two male suspects entered through the front door of the restaurant at 744 El Camino Real, walked behind the counter and confronted the lone employee, according to the San Mateo County Sheriff's Office.
One simulated a handgun under his sweatshirt and demanded cash. No weapon was actually seen, sheriff's Lt. Ray Lunny said.
The suspects took money from the register and exited through the front door. They were last seen walking south on El Camino Real.
Both are described as white males, ages 17 to 20, with thin builds. They both wore black, knit ski masks.
The robber who simulated a gun is described as about 5 feet 10 inches to 6 feet tall.
The other stands about 5 feet 5 inches to 5 feet 8 inches tall.
Though both were heavily disguised, investigators are still hoping for a break in the case.
"We're looking to see if there is any video," Lunny said.