If you're looking for a tastier alternative to the standard black bean veggie burger, just wander through the Essex Street Market until you stumble upon the hodgepodge stall that is Ni Japanese Delicacies. In this tiny temple to vegetarian and macrobiotic Japanese food you'll find the Forbidden Rice Burger ($10).
Instead of the usual patty made of mashed-up veggies and legumes, proprietor Saori Numata forms a pillow of black rice mixed with organic maitake mushrooms, carrots, and kale, with a smattering of white beans for creaminess. It's topped with a generous heap of baby arugula, pickled sweet pepper, and vegan herb mayo. A buttery brioche bun, carried straight from Pain d'Avignon next door, holds the burger together. If you want it vegan, you can substitute sprouted bread.
The rice is reminiscent of Thai black sticky rice commonly served for dessert, but here it's sugar-free and has a texture more akin to sushi rice. The patty's flavor is mild, and I could have used more of it to stand up to the bun, but the arugula and mayo keep it interesting, wholesome without tasting too much like health food.