In a small pot, heat black beans until bubbling and heated throughout (or use the microwave if you prefer!). If you decide to heat the entire can of black beans this may take up to 5 minutes. Set aside.
Place tortillas in a microwave-safe tortilla warmer and heat for 10 seconds intervals until tortillas are hot.
Assemble tacos by placing the warmed tortillas in a taco stand and equally dividing black beans and feta cheese into each. Garnish with hot sauce and cilantro. Enjoy!