Add black beans to a small saucepan over medium heat and add spices. Once it reaches a low boil, turn heat to low to keep warm, stirring occasionally.
Peel and chop plantains and heat a large metal or cast iron skillet over medium heat. Add plantains to a mixing bowl and toss with spices.
Once pan is hot, add coconut oil and plantains and spread into a single layer. Sauté on one side for 2-3 minutes, then flip and sauté on the other side for 2-3 minutes more. Turn down heat if browning too quickly. You're going for a caramelized effect. Set aside.
In the meantime, prep desired toppings and warm tortillas by wrapping in a damp cloth or paper towel and warming in the microwave for 20 seconds (or place tortillas directly on an oven rack for 1-2 minutes in a 350-degree F (176 C) oven).
To assemble, top tortillas with black beans, plantains and desired toppings. I preferred salsa, hot sauce, red onion, and cilantro. Ripe avocado would also make a great addition.