Add a splash of the oil to a saucepan and lightly saute the onions over medium heat. When they become translucent, stir in the black beans, cumin, and salsa verde. If your beans were unsalted- add a pinch to taste. Reduce to low and simmer until you need them.
Meanwhile, preheat the oven to 425. If using coconut oil, melt it over low heat. Dip the tortillas into the oil, one at a time, dabbing the oil off on to the next tortilla. Use just as much oil as you need- less is more.
Spread out on a baking sheet and place in the oven for about 4-6 minutes until lightly golden. You will probably want to flip the tortillas over at some point to even out the color.
When the tortillas and beans are both hot, it is time to assemble:
The crispy tortilla will be on the bottom.
Dollop on the black beans.
Add a sprinkle of cheese if using.
Top with the rest: shredded carrots & radishes, lettuce, and cilantro. Squeeze the lime on top and enjoy.
A drizzle of sour cream, yogurt or chipotle dressing will be a lovely addition.