The story behind Philippe’s and its famous French dip. (LA Times)

You can’t go back in time to ask Philippe “Frenchy” Mathieu, the founder of Philippe’s. But you can journey to that era, price-wise, on Monday when the North Alameda Street restaurant throws a centennial bash.

From 4 to 8 p.m., sandwiches (normally $5.35 to $6.50) will sell for 10 cents, and coffee (normally 9 cents) will be reduced to a nickel. (Tips of more than 20% for the servers might be in order this day.)