01 - Preheat the oven to 425°F. Line a baking sheet with parchment paper.
02 - In a large bowl, combine diced sweet potatoes, sliced onion, and chopped bell pepper with olive oil, ground cumin, smoked paprika, chili powder, ground coriander, salt, and black pepper. Mix well to coat evenly.
03 - Spread the seasoned vegetables evenly on the prepared baking sheet. Roast for 25 to 30 minutes, tossing once halfway through, until the vegetables are tender and caramelized. Remove from the oven and allow to cool for 5 minutes.
04 - Heat a large skillet over medium heat. Add the black beans and minced garlic, stirring occasionally for 2 to 3 minutes until warmed through.
05 - Heat the flour tortillas in a dry skillet or microwave until they are soft and pliable.
06 - On each tortilla, layer roasted vegetables, warmed black beans, shredded cheese if using, avocado slices, and a dollop of sour cream or Greek yogurt. Sprinkle with fresh chopped cilantro.
07 - Fold in the sides of each tortilla and roll tightly to enclose the filling.
08 - Place the burritos seam-side down in a skillet over medium heat. Toast each side for 2 to 3 minutes until golden brown and crisp.
09 - Serve the burritos warm with lime wedges on the side.