Preheat oven to 400 degrees.
Scrub, peel, and cube the potatoes into 1-inch cubes.
If using sweet potatoes, melt coconut oil and combine with salt, chipotle powder, garlic powder, paprika, and chili powder. If using russet potatoes, combine olive oil with same spices.
Toss the potatoes with oil-spice mixture.
Place on a parchment-lined baking sheet and roast for 25-30 minutes, until tender and crispy.
Meanwhile, place drained black beans into a saucepan. Combine with cumin, salt, and lime juice. Heat through.
Warm tortillas on both sides on a griddle or skillet over medium heat, until pliable, about 1 minute total. Keep warmed tortillas in a thin kitchen towel.
Serve potatoes and black beans with warmed tortillas and desired accompaniments.