I did do a fish dish with purple mashed potatoes but I am reasonably convinced that thinking outside of the box is a little too demanding for most people and I would hear comments like "that isnt meat" but if it isn't meat then what is it? I will let you ponder that one a while.
A good burger needs good fries and the best way to get good fries is to fry them twice, once to blanch and a second time to crispy them up.
Once the fries are done then make your burger, I like mine with mustard and mayo on a toasted bun with lettuce (shredded) tomato and red onion - oh and of course cheese, good ol' yellow american, add a strawberry milkshake and you are good to go.