Add veggie broth, quinoa and lime juice to a small sauce pan. Bring to a boil, cover and reduce to simmer for 12 – 15 minutes until all the liquid has been absorbed.
Remove from the heat and let cool for 10 - 15 minutes. Stir in lime zest, ½ cup cilantro and season with salt & pepper.
In a separate bowl, mash avocado until almost smooth. Stir in onion, lime juice and ¼ cup cilantro. Season with salt & pepper.
To assemble tacos, place ¼ - ½ cup of quinoa mixture onto the base of each tortilla. Top with black beans, cabbage and the guacamole. Garnish with cilantro (and/or hot sauce!) and enjoy immediately!