Dexter Burger is a small burger restaurant in Purley, South London, opened in mid-2015.
Their vegetarian burger is one of the most interesting veggie burgers I’ve had in a while, made from a mixture of raw and cooked beetroot along with vegetarian sausage mix (the excellent but now-elusive Sosmix), flavoured with fresh horseradish, and served in a brioche bun with a large slice of warm goat cheese.
According to one of the owners, when he was planning the restaurant his vegetarian friends forbade him from doing a mushroom “burger” (i.e. a grilled mushroom in a bun). I suspect they’re more than happy with the result; as a vegetable-loving omnivore I certainly am.
I’ll try the beef burger next time I go, but I think at some point I’ll also challenge them to come up with another similarly-inventive vegetarian option as one of their occasional specials. (The staff were all friendly, and happy to discuss the food.)