Place the black beans in a four-quart saucepan with about two teaspoons of the taco seasoning and a generous pinch of kosher salt. Stir to incorporate and set over low heat.
Slice the onion into slivers and the chilies into matchsticks. Toss with about a teaspoon of the taco seasoning. Set a wide skillet over high heat and apply vegetable or olive oil to form a generous layer on the bottom of the pan. Heat until smoking and then add the vegetables plus a big pinch of kosher salt.
Once the salt is integrated, do not disturb the vegetables for 3-5 minutes, or until they develop a deep char on one side. Toss the vegetables with tongs and continue to cook for another one to two minutes until all the vegetables are charred. Remove from heat.
Serve guacamole, beans, and vegetables with fresh corn tortillas and top with salsa verde.