In a skillet over medium heat, sauté chopped onion in a splash of oil until soft and golden-brown, about 5 minutes.

Add minced garlic, chopped chipotle pepper, cumin, and chili powder. Stir continuously for another 2-3 minutes until fragrant.

Stir in the rinsed black beans and vegetable stock into the skillet. Mash some of the beans while mixing. Let it simmer for 5-7 minutes.

Squeeze in the juice of fresh lime to finish the filling.

Wrap the corn tortillas in a damp paper towel and microwave them for about 30 seconds until warm.

Preheat the oven to 400°F (200°C) and lightly coat a sheet pan with oil.

Fill half of each tortilla with the black bean mixture and sprinkle with cheese. Fold tortillas over.

Bake the assembled tacos for 12-15 minutes, flipping them halfway through for even crispiness.

Remove from the oven, let them cool slightly, and serve with toppings.