Prep the produce: Dice the mango, bell pepper, and red onion. Mince the jalapeño and chop the cilantro.
Rinse and drain the black beans well to remove excess starch and sodium.
Make the salsa: In a large bowl, combine mango, black beans, bell pepper, red onion, jalapeño, and cilantro. Add lime juice, olive oil, cumin, and chili powder. Season with salt and pepper.
Stir gently so the mango holds its shape. Taste and adjust lime and salt.
Let it mingle: Set the salsa aside for 10 minutes. This short rest lets the flavors meld and slightly softens the onion and jalapeño.
Warm the tortillas: Heat a dry skillet over medium-high.
Warm each tortilla 20–30 seconds per side until pliable and lightly charred. Keep them stacked in a clean towel to stay warm.
Assemble: Layer warm tortillas with a generous scoop of mango black bean salsa. Add avocado slices and a sprinkle of queso fresco if using.
Finish with a squeeze of lime and a few drops of hot sauce.
Serve right away: Tacos are best enjoyed immediately while the tortillas are warm and the salsa is bright and juicy.