i always pass by fat boys twice a day on the way to school and finally got to try it!
you can either d.i.y. your burger or select a pre-concocted one from the menu.
kuma had the a lamb patty, fried egg with cheddar cheese burger.
i had the portobello mushroom with grilled chicken burger ($13.80). so good, i tell ya. both mushroom and chicken went really well together. i would totally go back again.
by the way, they do not charge gst or service charge.