Sliced pickled beetroot is a standard hamburger topping in Australia and New Zealand. You want nice, wide, thick slices the same size as your hamburger patty. Coupled with a pineapple ring and a fried egg plus whatever else you want, you’ve got the makings of the Perfect Hamburger...
(Mmmmmm-mmmm! I’ve just made myself hungry!)
Pickled beetroot sounds like an odd thing to add to a Hamburger, but once you’ve tried it every Hamburger you have thereafter will seem incomplete without it.
It must provide a ketchup effect - sweet and watery.
I can see how a slice of pickled beet would be good on a hamburger - don’t know that I’d want to try it coupled with a pineapple ring and a fried egg. Ha.
I love pickled beets on salad, or just served cold as a side dish with other veggies.