Fat Burger Goes Vegan / Vegan Milkshakes. Fat Burger just added vegan milkshakes to their menu, so it's time for a vegan taste test and put these Fat Burger vegan milk shakes to the test! I'm joined again my two friends Alvaro and Suzy who aren't vegan and enjoy regular dairy milk shakes. If these vegan milk shakes from Fat Burger can pass this test, we know they are on to something. It's great to see mainstream places like Fat Burger now serving vegan options. Fat Burger added the Impossible Burger recently, so you can now order a vegan burger and vegan milkshake at Fat Burger. This non-vegan duo also wants to try the Fat Burger Impossible Burger with this vegan milkshake, so be on the lookout for that vegan taste test soon. I hope you enjoy this Fat Burger vegan milkshake review.